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createplan.c
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1 /*-------------------------------------------------------------------------
2  *
3  * createplan.c
4  * Routines to create the desired plan for processing a query.
5  * Planning is complete, we just need to convert the selected
6  * Path into a Plan.
7  *
8  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
9  * Portions Copyright (c) 1994, Regents of the University of California
10  *
11  *
12  * IDENTIFICATION
13  * src/backend/optimizer/plan/createplan.c
14  *
15  *-------------------------------------------------------------------------
16  */
17 #include "postgres.h"
18 
19 #include <math.h>
20 
21 #include "access/sysattr.h"
22 #include "catalog/pg_class.h"
23 #include "foreign/fdwapi.h"
24 #include "miscadmin.h"
25 #include "nodes/extensible.h"
26 #include "nodes/makefuncs.h"
27 #include "nodes/nodeFuncs.h"
28 #include "optimizer/clauses.h"
29 #include "optimizer/cost.h"
30 #include "optimizer/optimizer.h"
31 #include "optimizer/paramassign.h"
32 #include "optimizer/pathnode.h"
33 #include "optimizer/paths.h"
34 #include "optimizer/placeholder.h"
35 #include "optimizer/plancat.h"
36 #include "optimizer/planmain.h"
37 #include "optimizer/prep.h"
38 #include "optimizer/restrictinfo.h"
39 #include "optimizer/subselect.h"
40 #include "optimizer/tlist.h"
41 #include "parser/parse_clause.h"
42 #include "parser/parsetree.h"
43 #include "partitioning/partprune.h"
44 #include "utils/lsyscache.h"
45 
46 
47 /*
48  * Flag bits that can appear in the flags argument of create_plan_recurse().
49  * These can be OR-ed together.
50  *
51  * CP_EXACT_TLIST specifies that the generated plan node must return exactly
52  * the tlist specified by the path's pathtarget (this overrides both
53  * CP_SMALL_TLIST and CP_LABEL_TLIST, if those are set). Otherwise, the
54  * plan node is allowed to return just the Vars and PlaceHolderVars needed
55  * to evaluate the pathtarget.
56  *
57  * CP_SMALL_TLIST specifies that a narrower tlist is preferred. This is
58  * passed down by parent nodes such as Sort and Hash, which will have to
59  * store the returned tuples.
60  *
61  * CP_LABEL_TLIST specifies that the plan node must return columns matching
62  * any sortgrouprefs specified in its pathtarget, with appropriate
63  * ressortgroupref labels. This is passed down by parent nodes such as Sort
64  * and Group, which need these values to be available in their inputs.
65  *
66  * CP_IGNORE_TLIST specifies that the caller plans to replace the targetlist,
67  * and therefore it doesn't matter a bit what target list gets generated.
68  */
69 #define CP_EXACT_TLIST 0x0001 /* Plan must return specified tlist */
70 #define CP_SMALL_TLIST 0x0002 /* Prefer narrower tlists */
71 #define CP_LABEL_TLIST 0x0004 /* tlist must contain sortgrouprefs */
72 #define CP_IGNORE_TLIST 0x0008 /* caller will replace tlist */
73 
74 
75 static Plan *create_plan_recurse(PlannerInfo *root, Path *best_path,
76  int flags);
77 static Plan *create_scan_plan(PlannerInfo *root, Path *best_path,
78  int flags);
79 static List *build_path_tlist(PlannerInfo *root, Path *path);
80 static bool use_physical_tlist(PlannerInfo *root, Path *path, int flags);
81 static List *get_gating_quals(PlannerInfo *root, List *quals);
83  List *gating_quals);
84 static Plan *create_join_plan(PlannerInfo *root, JoinPath *best_path);
85 static bool mark_async_capable_plan(Plan *plan, Path *path);
87  int flags);
89  int flags);
91  GroupResultPath *best_path);
94  int flags);
96  int flags);
98  int flags);
101  ProjectionPath *best_path,
102  int flags);
103 static Plan *inject_projection_plan(Plan *subplan, List *tlist, bool parallel_safe);
104 static Sort *create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags);
106  IncrementalSortPath *best_path, int flags);
107 static Group *create_group_plan(PlannerInfo *root, GroupPath *best_path);
109  int flags);
110 static Agg *create_agg_plan(PlannerInfo *root, AggPath *best_path);
114 static SetOp *create_setop_plan(PlannerInfo *root, SetOpPath *best_path,
115  int flags);
118  int flags);
120 static Limit *create_limit_plan(PlannerInfo *root, LimitPath *best_path,
121  int flags);
122 static SeqScan *create_seqscan_plan(PlannerInfo *root, Path *best_path,
123  List *tlist, List *scan_clauses);
125  List *tlist, List *scan_clauses);
127  List *tlist, List *scan_clauses, bool indexonly);
129  BitmapHeapPath *best_path,
130  List *tlist, List *scan_clauses);
131 static Plan *create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
132  List **qual, List **indexqual, List **indexECs);
133 static void bitmap_subplan_mark_shared(Plan *plan);
134 static TidScan *create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
135  List *tlist, List *scan_clauses);
137  TidRangePath *best_path,
138  List *tlist,
139  List *scan_clauses);
141  SubqueryScanPath *best_path,
142  List *tlist, List *scan_clauses);
144  List *tlist, List *scan_clauses);
146  List *tlist, List *scan_clauses);
148  List *tlist, List *scan_clauses);
149 static CteScan *create_ctescan_plan(PlannerInfo *root, Path *best_path,
150  List *tlist, List *scan_clauses);
152  Path *best_path, List *tlist, List *scan_clauses);
153 static Result *create_resultscan_plan(PlannerInfo *root, Path *best_path,
154  List *tlist, List *scan_clauses);
156  List *tlist, List *scan_clauses);
158  List *tlist, List *scan_clauses);
160  CustomPath *best_path,
161  List *tlist, List *scan_clauses);
167 static void fix_indexqual_references(PlannerInfo *root, IndexPath *index_path,
168  List **stripped_indexquals_p,
169  List **fixed_indexquals_p);
172  IndexOptInfo *index, int indexcol,
173  Node *clause, List *indexcolnos);
174 static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index, int indexcol);
175 static List *get_switched_clauses(List *clauses, Relids outerrelids);
176 static List *order_qual_clauses(PlannerInfo *root, List *clauses);
177 static void copy_generic_path_info(Plan *dest, Path *src);
178 static void copy_plan_costsize(Plan *dest, Plan *src);
180  double limit_tuples);
181 static SeqScan *make_seqscan(List *qptlist, List *qpqual, Index scanrelid);
182 static SampleScan *make_samplescan(List *qptlist, List *qpqual, Index scanrelid,
183  TableSampleClause *tsc);
184 static IndexScan *make_indexscan(List *qptlist, List *qpqual, Index scanrelid,
185  Oid indexid, List *indexqual, List *indexqualorig,
186  List *indexorderby, List *indexorderbyorig,
187  List *indexorderbyops,
188  ScanDirection indexscandir);
189 static IndexOnlyScan *make_indexonlyscan(List *qptlist, List *qpqual,
190  Index scanrelid, Oid indexid,
191  List *indexqual, List *recheckqual,
192  List *indexorderby,
193  List *indextlist,
194  ScanDirection indexscandir);
195 static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
196  List *indexqual,
197  List *indexqualorig);
198 static BitmapHeapScan *make_bitmap_heapscan(List *qptlist,
199  List *qpqual,
200  Plan *lefttree,
201  List *bitmapqualorig,
202  Index scanrelid);
203 static TidScan *make_tidscan(List *qptlist, List *qpqual, Index scanrelid,
204  List *tidquals);
205 static TidRangeScan *make_tidrangescan(List *qptlist, List *qpqual,
206  Index scanrelid, List *tidrangequals);
207 static SubqueryScan *make_subqueryscan(List *qptlist,
208  List *qpqual,
209  Index scanrelid,
210  Plan *subplan);
211 static FunctionScan *make_functionscan(List *qptlist, List *qpqual,
212  Index scanrelid, List *functions, bool funcordinality);
213 static ValuesScan *make_valuesscan(List *qptlist, List *qpqual,
214  Index scanrelid, List *values_lists);
215 static TableFuncScan *make_tablefuncscan(List *qptlist, List *qpqual,
216  Index scanrelid, TableFunc *tablefunc);
217 static CteScan *make_ctescan(List *qptlist, List *qpqual,
218  Index scanrelid, int ctePlanId, int cteParam);
219 static NamedTuplestoreScan *make_namedtuplestorescan(List *qptlist, List *qpqual,
220  Index scanrelid, char *enrname);
221 static WorkTableScan *make_worktablescan(List *qptlist, List *qpqual,
222  Index scanrelid, int wtParam);
224  Plan *lefttree,
225  Plan *righttree,
226  int wtParam,
227  List *distinctList,
228  long numGroups);
229 static BitmapAnd *make_bitmap_and(List *bitmapplans);
230 static BitmapOr *make_bitmap_or(List *bitmapplans);
231 static NestLoop *make_nestloop(List *tlist,
232  List *joinclauses, List *otherclauses, List *nestParams,
233  Plan *lefttree, Plan *righttree,
234  JoinType jointype, bool inner_unique);
235 static HashJoin *make_hashjoin(List *tlist,
236  List *joinclauses, List *otherclauses,
237  List *hashclauses,
238  List *hashoperators, List *hashcollations,
239  List *hashkeys,
240  Plan *lefttree, Plan *righttree,
241  JoinType jointype, bool inner_unique);
242 static Hash *make_hash(Plan *lefttree,
243  List *hashkeys,
244  Oid skewTable,
245  AttrNumber skewColumn,
246  bool skewInherit);
247 static MergeJoin *make_mergejoin(List *tlist,
248  List *joinclauses, List *otherclauses,
249  List *mergeclauses,
250  Oid *mergefamilies,
251  Oid *mergecollations,
252  int *mergestrategies,
253  bool *mergenullsfirst,
254  Plan *lefttree, Plan *righttree,
255  JoinType jointype, bool inner_unique,
256  bool skip_mark_restore);
257 static Sort *make_sort(Plan *lefttree, int numCols,
258  AttrNumber *sortColIdx, Oid *sortOperators,
259  Oid *collations, bool *nullsFirst);
260 static IncrementalSort *make_incrementalsort(Plan *lefttree,
261  int numCols, int nPresortedCols,
262  AttrNumber *sortColIdx, Oid *sortOperators,
263  Oid *collations, bool *nullsFirst);
264 static Plan *prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
265  Relids relids,
266  const AttrNumber *reqColIdx,
267  bool adjust_tlist_in_place,
268  int *p_numsortkeys,
269  AttrNumber **p_sortColIdx,
270  Oid **p_sortOperators,
271  Oid **p_collations,
272  bool **p_nullsFirst);
273 static Sort *make_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
274  Relids relids);
276  List *pathkeys, Relids relids, int nPresortedCols);
277 static Sort *make_sort_from_groupcols(List *groupcls,
278  AttrNumber *grpColIdx,
279  Plan *lefttree);
280 static Material *make_material(Plan *lefttree);
281 static Memoize *make_memoize(Plan *lefttree, Oid *hashoperators,
282  Oid *collations, List *param_exprs,
283  bool singlerow, bool binary_mode,
284  uint32 est_entries, Bitmapset *keyparamids);
285 static WindowAgg *make_windowagg(List *tlist, Index winref,
286  int partNumCols, AttrNumber *partColIdx, Oid *partOperators, Oid *partCollations,
287  int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations,
288  int frameOptions, Node *startOffset, Node *endOffset,
289  Oid startInRangeFunc, Oid endInRangeFunc,
290  Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst,
291  List *runCondition, List *qual, bool topWindow,
292  Plan *lefttree);
293 static Group *make_group(List *tlist, List *qual, int numGroupCols,
294  AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations,
295  Plan *lefttree);
296 static Unique *make_unique_from_sortclauses(Plan *lefttree, List *distinctList);
297 static Unique *make_unique_from_pathkeys(Plan *lefttree,
298  List *pathkeys, int numCols);
299 static Gather *make_gather(List *qptlist, List *qpqual,
300  int nworkers, int rescan_param, bool single_copy, Plan *subplan);
301 static SetOp *make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
302  List *distinctList, AttrNumber flagColIdx, int firstFlag,
303  long numGroups);
304 static LockRows *make_lockrows(Plan *lefttree, List *rowMarks, int epqParam);
305 static Result *make_result(List *tlist, Node *resconstantqual, Plan *subplan);
306 static ProjectSet *make_project_set(List *tlist, Plan *subplan);
308  CmdType operation, bool canSetTag,
309  Index nominalRelation, Index rootRelation,
310  bool partColsUpdated,
311  List *resultRelations,
312  List *updateColnosLists,
313  List *withCheckOptionLists, List *returningLists,
314  List *rowMarks, OnConflictExpr *onconflict,
315  List *mergeActionLists, List *mergeJoinConditions,
316  int epqParam);
318  GatherMergePath *best_path);
319 
320 
321 /*
322  * create_plan
323  * Creates the access plan for a query by recursively processing the
324  * desired tree of pathnodes, starting at the node 'best_path'. For
325  * every pathnode found, we create a corresponding plan node containing
326  * appropriate id, target list, and qualification information.
327  *
328  * The tlists and quals in the plan tree are still in planner format,
329  * ie, Vars still correspond to the parser's numbering. This will be
330  * fixed later by setrefs.c.
331  *
332  * best_path is the best access path
333  *
334  * Returns a Plan tree.
335  */
336 Plan *
338 {
339  Plan *plan;
340 
341  /* plan_params should not be in use in current query level */
342  Assert(root->plan_params == NIL);
343 
344  /* Initialize this module's workspace in PlannerInfo */
345  root->curOuterRels = NULL;
346  root->curOuterParams = NIL;
347 
348  /* Recursively process the path tree, demanding the correct tlist result */
350 
351  /*
352  * Make sure the topmost plan node's targetlist exposes the original
353  * column names and other decorative info. Targetlists generated within
354  * the planner don't bother with that stuff, but we must have it on the
355  * top-level tlist seen at execution time. However, ModifyTable plan
356  * nodes don't have a tlist matching the querytree targetlist.
357  */
358  if (!IsA(plan, ModifyTable))
359  apply_tlist_labeling(plan->targetlist, root->processed_tlist);
360 
361  /*
362  * Attach any initPlans created in this query level to the topmost plan
363  * node. (In principle the initplans could go in any plan node at or
364  * above where they're referenced, but there seems no reason to put them
365  * any lower than the topmost node for the query level. Also, see
366  * comments for SS_finalize_plan before you try to change this.)
367  */
369 
370  /* Check we successfully assigned all NestLoopParams to plan nodes */
371  if (root->curOuterParams != NIL)
372  elog(ERROR, "failed to assign all NestLoopParams to plan nodes");
373 
374  /*
375  * Reset plan_params to ensure param IDs used for nestloop params are not
376  * re-used later
377  */
378  root->plan_params = NIL;
379 
380  return plan;
381 }
382 
383 /*
384  * create_plan_recurse
385  * Recursive guts of create_plan().
386  */
387 static Plan *
388 create_plan_recurse(PlannerInfo *root, Path *best_path, int flags)
389 {
390  Plan *plan;
391 
392  /* Guard against stack overflow due to overly complex plans */
394 
395  switch (best_path->pathtype)
396  {
397  case T_SeqScan:
398  case T_SampleScan:
399  case T_IndexScan:
400  case T_IndexOnlyScan:
401  case T_BitmapHeapScan:
402  case T_TidScan:
403  case T_TidRangeScan:
404  case T_SubqueryScan:
405  case T_FunctionScan:
406  case T_TableFuncScan:
407  case T_ValuesScan:
408  case T_CteScan:
409  case T_WorkTableScan:
410  case T_NamedTuplestoreScan:
411  case T_ForeignScan:
412  case T_CustomScan:
413  plan = create_scan_plan(root, best_path, flags);
414  break;
415  case T_HashJoin:
416  case T_MergeJoin:
417  case T_NestLoop:
419  (JoinPath *) best_path);
420  break;
421  case T_Append:
423  (AppendPath *) best_path,
424  flags);
425  break;
426  case T_MergeAppend:
428  (MergeAppendPath *) best_path,
429  flags);
430  break;
431  case T_Result:
432  if (IsA(best_path, ProjectionPath))
433  {
435  (ProjectionPath *) best_path,
436  flags);
437  }
438  else if (IsA(best_path, MinMaxAggPath))
439  {
441  (MinMaxAggPath *) best_path);
442  }
443  else if (IsA(best_path, GroupResultPath))
444  {
446  (GroupResultPath *) best_path);
447  }
448  else
449  {
450  /* Simple RTE_RESULT base relation */
451  Assert(IsA(best_path, Path));
452  plan = create_scan_plan(root, best_path, flags);
453  }
454  break;
455  case T_ProjectSet:
457  (ProjectSetPath *) best_path);
458  break;
459  case T_Material:
461  (MaterialPath *) best_path,
462  flags);
463  break;
464  case T_Memoize:
466  (MemoizePath *) best_path,
467  flags);
468  break;
469  case T_Unique:
470  if (IsA(best_path, UpperUniquePath))
471  {
473  (UpperUniquePath *) best_path,
474  flags);
475  }
476  else
477  {
478  Assert(IsA(best_path, UniquePath));
480  (UniquePath *) best_path,
481  flags);
482  }
483  break;
484  case T_Gather:
486  (GatherPath *) best_path);
487  break;
488  case T_Sort:
490  (SortPath *) best_path,
491  flags);
492  break;
493  case T_IncrementalSort:
495  (IncrementalSortPath *) best_path,
496  flags);
497  break;
498  case T_Group:
500  (GroupPath *) best_path);
501  break;
502  case T_Agg:
503  if (IsA(best_path, GroupingSetsPath))
505  (GroupingSetsPath *) best_path);
506  else
507  {
508  Assert(IsA(best_path, AggPath));
510  (AggPath *) best_path);
511  }
512  break;
513  case T_WindowAgg:
515  (WindowAggPath *) best_path);
516  break;
517  case T_SetOp:
519  (SetOpPath *) best_path,
520  flags);
521  break;
522  case T_RecursiveUnion:
524  (RecursiveUnionPath *) best_path);
525  break;
526  case T_LockRows:
528  (LockRowsPath *) best_path,
529  flags);
530  break;
531  case T_ModifyTable:
533  (ModifyTablePath *) best_path);
534  break;
535  case T_Limit:
537  (LimitPath *) best_path,
538  flags);
539  break;
540  case T_GatherMerge:
542  (GatherMergePath *) best_path);
543  break;
544  default:
545  elog(ERROR, "unrecognized node type: %d",
546  (int) best_path->pathtype);
547  plan = NULL; /* keep compiler quiet */
548  break;
549  }
550 
551  return plan;
552 }
553 
554 /*
555  * create_scan_plan
556  * Create a scan plan for the parent relation of 'best_path'.
557  */
558 static Plan *
559 create_scan_plan(PlannerInfo *root, Path *best_path, int flags)
560 {
561  RelOptInfo *rel = best_path->parent;
562  List *scan_clauses;
563  List *gating_clauses;
564  List *tlist;
565  Plan *plan;
566 
567  /*
568  * Extract the relevant restriction clauses from the parent relation. The
569  * executor must apply all these restrictions during the scan, except for
570  * pseudoconstants which we'll take care of below.
571  *
572  * If this is a plain indexscan or index-only scan, we need not consider
573  * restriction clauses that are implied by the index's predicate, so use
574  * indrestrictinfo not baserestrictinfo. Note that we can't do that for
575  * bitmap indexscans, since there's not necessarily a single index
576  * involved; but it doesn't matter since create_bitmap_scan_plan() will be
577  * able to get rid of such clauses anyway via predicate proof.
578  */
579  switch (best_path->pathtype)
580  {
581  case T_IndexScan:
582  case T_IndexOnlyScan:
583  scan_clauses = castNode(IndexPath, best_path)->indexinfo->indrestrictinfo;
584  break;
585  default:
586  scan_clauses = rel->baserestrictinfo;
587  break;
588  }
589 
590  /*
591  * If this is a parameterized scan, we also need to enforce all the join
592  * clauses available from the outer relation(s).
593  *
594  * For paranoia's sake, don't modify the stored baserestrictinfo list.
595  */
596  if (best_path->param_info)
597  scan_clauses = list_concat_copy(scan_clauses,
598  best_path->param_info->ppi_clauses);
599 
600  /*
601  * Detect whether we have any pseudoconstant quals to deal with. Then, if
602  * we'll need a gating Result node, it will be able to project, so there
603  * are no requirements on the child's tlist.
604  *
605  * If this replaces a join, it must be a foreign scan or a custom scan,
606  * and the FDW or the custom scan provider would have stored in the best
607  * path the list of RestrictInfo nodes to apply to the join; check against
608  * that list in that case.
609  */
610  if (IS_JOIN_REL(rel))
611  {
612  List *join_clauses;
613 
614  Assert(best_path->pathtype == T_ForeignScan ||
615  best_path->pathtype == T_CustomScan);
616  if (best_path->pathtype == T_ForeignScan)
617  join_clauses = ((ForeignPath *) best_path)->fdw_restrictinfo;
618  else
619  join_clauses = ((CustomPath *) best_path)->custom_restrictinfo;
620 
621  gating_clauses = get_gating_quals(root, join_clauses);
622  }
623  else
624  gating_clauses = get_gating_quals(root, scan_clauses);
625  if (gating_clauses)
626  flags = 0;
627 
628  /*
629  * For table scans, rather than using the relation targetlist (which is
630  * only those Vars actually needed by the query), we prefer to generate a
631  * tlist containing all Vars in order. This will allow the executor to
632  * optimize away projection of the table tuples, if possible.
633  *
634  * But if the caller is going to ignore our tlist anyway, then don't
635  * bother generating one at all. We use an exact equality test here, so
636  * that this only applies when CP_IGNORE_TLIST is the only flag set.
637  */
638  if (flags == CP_IGNORE_TLIST)
639  {
640  tlist = NULL;
641  }
642  else if (use_physical_tlist(root, best_path, flags))
643  {
644  if (best_path->pathtype == T_IndexOnlyScan)
645  {
646  /* For index-only scan, the preferred tlist is the index's */
647  tlist = copyObject(((IndexPath *) best_path)->indexinfo->indextlist);
648 
649  /*
650  * Transfer sortgroupref data to the replacement tlist, if
651  * requested (use_physical_tlist checked that this will work).
652  */
653  if (flags & CP_LABEL_TLIST)
654  apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget);
655  }
656  else
657  {
658  tlist = build_physical_tlist(root, rel);
659  if (tlist == NIL)
660  {
661  /* Failed because of dropped cols, so use regular method */
662  tlist = build_path_tlist(root, best_path);
663  }
664  else
665  {
666  /* As above, transfer sortgroupref data to replacement tlist */
667  if (flags & CP_LABEL_TLIST)
668  apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget);
669  }
670  }
671  }
672  else
673  {
674  tlist = build_path_tlist(root, best_path);
675  }
676 
677  switch (best_path->pathtype)
678  {
679  case T_SeqScan:
681  best_path,
682  tlist,
683  scan_clauses);
684  break;
685 
686  case T_SampleScan:
688  best_path,
689  tlist,
690  scan_clauses);
691  break;
692 
693  case T_IndexScan:
695  (IndexPath *) best_path,
696  tlist,
697  scan_clauses,
698  false);
699  break;
700 
701  case T_IndexOnlyScan:
703  (IndexPath *) best_path,
704  tlist,
705  scan_clauses,
706  true);
707  break;
708 
709  case T_BitmapHeapScan:
711  (BitmapHeapPath *) best_path,
712  tlist,
713  scan_clauses);
714  break;
715 
716  case T_TidScan:
718  (TidPath *) best_path,
719  tlist,
720  scan_clauses);
721  break;
722 
723  case T_TidRangeScan:
725  (TidRangePath *) best_path,
726  tlist,
727  scan_clauses);
728  break;
729 
730  case T_SubqueryScan:
732  (SubqueryScanPath *) best_path,
733  tlist,
734  scan_clauses);
735  break;
736 
737  case T_FunctionScan:
739  best_path,
740  tlist,
741  scan_clauses);
742  break;
743 
744  case T_TableFuncScan:
746  best_path,
747  tlist,
748  scan_clauses);
749  break;
750 
751  case T_ValuesScan:
753  best_path,
754  tlist,
755  scan_clauses);
756  break;
757 
758  case T_CteScan:
760  best_path,
761  tlist,
762  scan_clauses);
763  break;
764 
765  case T_NamedTuplestoreScan:
767  best_path,
768  tlist,
769  scan_clauses);
770  break;
771 
772  case T_Result:
774  best_path,
775  tlist,
776  scan_clauses);
777  break;
778 
779  case T_WorkTableScan:
781  best_path,
782  tlist,
783  scan_clauses);
784  break;
785 
786  case T_ForeignScan:
788  (ForeignPath *) best_path,
789  tlist,
790  scan_clauses);
791  break;
792 
793  case T_CustomScan:
795  (CustomPath *) best_path,
796  tlist,
797  scan_clauses);
798  break;
799 
800  default:
801  elog(ERROR, "unrecognized node type: %d",
802  (int) best_path->pathtype);
803  plan = NULL; /* keep compiler quiet */
804  break;
805  }
806 
807  /*
808  * If there are any pseudoconstant clauses attached to this node, insert a
809  * gating Result node that evaluates the pseudoconstants as one-time
810  * quals.
811  */
812  if (gating_clauses)
813  plan = create_gating_plan(root, best_path, plan, gating_clauses);
814 
815  return plan;
816 }
817 
818 /*
819  * Build a target list (ie, a list of TargetEntry) for the Path's output.
820  *
821  * This is almost just make_tlist_from_pathtarget(), but we also have to
822  * deal with replacing nestloop params.
823  */
824 static List *
826 {
827  List *tlist = NIL;
828  Index *sortgrouprefs = path->pathtarget->sortgrouprefs;
829  int resno = 1;
830  ListCell *v;
831 
832  foreach(v, path->pathtarget->exprs)
833  {
834  Node *node = (Node *) lfirst(v);
835  TargetEntry *tle;
836 
837  /*
838  * If it's a parameterized path, there might be lateral references in
839  * the tlist, which need to be replaced with Params. There's no need
840  * to remake the TargetEntry nodes, so apply this to each list item
841  * separately.
842  */
843  if (path->param_info)
844  node = replace_nestloop_params(root, node);
845 
846  tle = makeTargetEntry((Expr *) node,
847  resno,
848  NULL,
849  false);
850  if (sortgrouprefs)
851  tle->ressortgroupref = sortgrouprefs[resno - 1];
852 
853  tlist = lappend(tlist, tle);
854  resno++;
855  }
856  return tlist;
857 }
858 
859 /*
860  * use_physical_tlist
861  * Decide whether to use a tlist matching relation structure,
862  * rather than only those Vars actually referenced.
863  */
864 static bool
866 {
867  RelOptInfo *rel = path->parent;
868  int i;
869  ListCell *lc;
870 
871  /*
872  * Forget it if either exact tlist or small tlist is demanded.
873  */
874  if (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST))
875  return false;
876 
877  /*
878  * We can do this for real relation scans, subquery scans, function scans,
879  * tablefunc scans, values scans, and CTE scans (but not for, eg, joins).
880  */
881  if (rel->rtekind != RTE_RELATION &&
882  rel->rtekind != RTE_SUBQUERY &&
883  rel->rtekind != RTE_FUNCTION &&
884  rel->rtekind != RTE_TABLEFUNC &&
885  rel->rtekind != RTE_VALUES &&
886  rel->rtekind != RTE_CTE)
887  return false;
888 
889  /*
890  * Can't do it with inheritance cases either (mainly because Append
891  * doesn't project; this test may be unnecessary now that
892  * create_append_plan instructs its children to return an exact tlist).
893  */
894  if (rel->reloptkind != RELOPT_BASEREL)
895  return false;
896 
897  /*
898  * Also, don't do it to a CustomPath; the premise that we're extracting
899  * columns from a simple physical tuple is unlikely to hold for those.
900  * (When it does make sense, the custom path creator can set up the path's
901  * pathtarget that way.)
902  */
903  if (IsA(path, CustomPath))
904  return false;
905 
906  /*
907  * If a bitmap scan's tlist is empty, keep it as-is. This may allow the
908  * executor to skip heap page fetches, and in any case, the benefit of
909  * using a physical tlist instead would be minimal.
910  */
911  if (IsA(path, BitmapHeapPath) &&
912  path->pathtarget->exprs == NIL)
913  return false;
914 
915  /*
916  * Can't do it if any system columns or whole-row Vars are requested.
917  * (This could possibly be fixed but would take some fragile assumptions
918  * in setrefs.c, I think.)
919  */
920  for (i = rel->min_attr; i <= 0; i++)
921  {
922  if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
923  return false;
924  }
925 
926  /*
927  * Can't do it if the rel is required to emit any placeholder expressions,
928  * either.
929  */
930  foreach(lc, root->placeholder_list)
931  {
932  PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
933 
934  if (bms_nonempty_difference(phinfo->ph_needed, rel->relids) &&
935  bms_is_subset(phinfo->ph_eval_at, rel->relids))
936  return false;
937  }
938 
939  /*
940  * For an index-only scan, the "physical tlist" is the index's indextlist.
941  * We can only return that without a projection if all the index's columns
942  * are returnable.
943  */
944  if (path->pathtype == T_IndexOnlyScan)
945  {
946  IndexOptInfo *indexinfo = ((IndexPath *) path)->indexinfo;
947 
948  for (i = 0; i < indexinfo->ncolumns; i++)
949  {
950  if (!indexinfo->canreturn[i])
951  return false;
952  }
953  }
954 
955  /*
956  * Also, can't do it if CP_LABEL_TLIST is specified and path is requested
957  * to emit any sort/group columns that are not simple Vars. (If they are
958  * simple Vars, they should appear in the physical tlist, and
959  * apply_pathtarget_labeling_to_tlist will take care of getting them
960  * labeled again.) We also have to check that no two sort/group columns
961  * are the same Var, else that element of the physical tlist would need
962  * conflicting ressortgroupref labels.
963  */
964  if ((flags & CP_LABEL_TLIST) && path->pathtarget->sortgrouprefs)
965  {
966  Bitmapset *sortgroupatts = NULL;
967 
968  i = 0;
969  foreach(lc, path->pathtarget->exprs)
970  {
971  Expr *expr = (Expr *) lfirst(lc);
972 
973  if (path->pathtarget->sortgrouprefs[i])
974  {
975  if (expr && IsA(expr, Var))
976  {
977  int attno = ((Var *) expr)->varattno;
978 
980  if (bms_is_member(attno, sortgroupatts))
981  return false;
982  sortgroupatts = bms_add_member(sortgroupatts, attno);
983  }
984  else
985  return false;
986  }
987  i++;
988  }
989  }
990 
991  return true;
992 }
993 
994 /*
995  * get_gating_quals
996  * See if there are pseudoconstant quals in a node's quals list
997  *
998  * If the node's quals list includes any pseudoconstant quals,
999  * return just those quals.
1000  */
1001 static List *
1003 {
1004  /* No need to look if we know there are no pseudoconstants */
1005  if (!root->hasPseudoConstantQuals)
1006  return NIL;
1007 
1008  /* Sort into desirable execution order while still in RestrictInfo form */
1009  quals = order_qual_clauses(root, quals);
1010 
1011  /* Pull out any pseudoconstant quals from the RestrictInfo list */
1012  return extract_actual_clauses(quals, true);
1013 }
1014 
1015 /*
1016  * create_gating_plan
1017  * Deal with pseudoconstant qual clauses
1018  *
1019  * Add a gating Result node atop the already-built plan.
1020  */
1021 static Plan *
1023  List *gating_quals)
1024 {
1025  Plan *gplan;
1026  Plan *splan;
1027 
1028  Assert(gating_quals);
1029 
1030  /*
1031  * We might have a trivial Result plan already. Stacking one Result atop
1032  * another is silly, so if that applies, just discard the input plan.
1033  * (We're assuming its targetlist is uninteresting; it should be either
1034  * the same as the result of build_path_tlist, or a simplified version.)
1035  */
1036  splan = plan;
1037  if (IsA(plan, Result))
1038  {
1039  Result *rplan = (Result *) plan;
1040 
1041  if (rplan->plan.lefttree == NULL &&
1042  rplan->resconstantqual == NULL)
1043  splan = NULL;
1044  }
1045 
1046  /*
1047  * Since we need a Result node anyway, always return the path's requested
1048  * tlist; that's never a wrong choice, even if the parent node didn't ask
1049  * for CP_EXACT_TLIST.
1050  */
1051  gplan = (Plan *) make_result(build_path_tlist(root, path),
1052  (Node *) gating_quals,
1053  splan);
1054 
1055  /*
1056  * Notice that we don't change cost or size estimates when doing gating.
1057  * The costs of qual eval were already included in the subplan's cost.
1058  * Leaving the size alone amounts to assuming that the gating qual will
1059  * succeed, which is the conservative estimate for planning upper queries.
1060  * We certainly don't want to assume the output size is zero (unless the
1061  * gating qual is actually constant FALSE, and that case is dealt with in
1062  * clausesel.c). Interpolating between the two cases is silly, because it
1063  * doesn't reflect what will really happen at runtime, and besides which
1064  * in most cases we have only a very bad idea of the probability of the
1065  * gating qual being true.
1066  */
1067  copy_plan_costsize(gplan, plan);
1068 
1069  /* Gating quals could be unsafe, so better use the Path's safety flag */
1070  gplan->parallel_safe = path->parallel_safe;
1071 
1072  return gplan;
1073 }
1074 
1075 /*
1076  * create_join_plan
1077  * Create a join plan for 'best_path' and (recursively) plans for its
1078  * inner and outer paths.
1079  */
1080 static Plan *
1082 {
1083  Plan *plan;
1084  List *gating_clauses;
1085 
1086  switch (best_path->path.pathtype)
1087  {
1088  case T_MergeJoin:
1090  (MergePath *) best_path);
1091  break;
1092  case T_HashJoin:
1094  (HashPath *) best_path);
1095  break;
1096  case T_NestLoop:
1098  (NestPath *) best_path);
1099  break;
1100  default:
1101  elog(ERROR, "unrecognized node type: %d",
1102  (int) best_path->path.pathtype);
1103  plan = NULL; /* keep compiler quiet */
1104  break;
1105  }
1106 
1107  /*
1108  * If there are any pseudoconstant clauses attached to this node, insert a
1109  * gating Result node that evaluates the pseudoconstants as one-time
1110  * quals.
1111  */
1112  gating_clauses = get_gating_quals(root, best_path->joinrestrictinfo);
1113  if (gating_clauses)
1114  plan = create_gating_plan(root, (Path *) best_path, plan,
1115  gating_clauses);
1116 
1117 #ifdef NOT_USED
1118 
1119  /*
1120  * * Expensive function pullups may have pulled local predicates * into
1121  * this path node. Put them in the qpqual of the plan node. * JMH,
1122  * 6/15/92
1123  */
1124  if (get_loc_restrictinfo(best_path) != NIL)
1125  set_qpqual((Plan) plan,
1126  list_concat(get_qpqual((Plan) plan),
1127  get_actual_clauses(get_loc_restrictinfo(best_path))));
1128 #endif
1129 
1130  return plan;
1131 }
1132 
1133 /*
1134  * mark_async_capable_plan
1135  * Check whether the Plan node created from a Path node is async-capable,
1136  * and if so, mark the Plan node as such and return true, otherwise
1137  * return false.
1138  */
1139 static bool
1141 {
1142  switch (nodeTag(path))
1143  {
1144  case T_SubqueryScanPath:
1145  {
1146  SubqueryScan *scan_plan = (SubqueryScan *) plan;
1147 
1148  /*
1149  * If the generated plan node includes a gating Result node,
1150  * we can't execute it asynchronously.
1151  */
1152  if (IsA(plan, Result))
1153  return false;
1154 
1155  /*
1156  * If a SubqueryScan node atop of an async-capable plan node
1157  * is deletable, consider it as async-capable.
1158  */
1159  if (trivial_subqueryscan(scan_plan) &&
1160  mark_async_capable_plan(scan_plan->subplan,
1161  ((SubqueryScanPath *) path)->subpath))
1162  break;
1163  return false;
1164  }
1165  case T_ForeignPath:
1166  {
1167  FdwRoutine *fdwroutine = path->parent->fdwroutine;
1168 
1169  /*
1170  * If the generated plan node includes a gating Result node,
1171  * we can't execute it asynchronously.
1172  */
1173  if (IsA(plan, Result))
1174  return false;
1175 
1176  Assert(fdwroutine != NULL);
1177  if (fdwroutine->IsForeignPathAsyncCapable != NULL &&
1178  fdwroutine->IsForeignPathAsyncCapable((ForeignPath *) path))
1179  break;
1180  return false;
1181  }
1182  case T_ProjectionPath:
1183 
1184  /*
1185  * If the generated plan node includes a Result node for the
1186  * projection, we can't execute it asynchronously.
1187  */
1188  if (IsA(plan, Result))
1189  return false;
1190 
1191  /*
1192  * create_projection_plan() would have pulled up the subplan, so
1193  * check the capability using the subpath.
1194  */
1196  ((ProjectionPath *) path)->subpath))
1197  return true;
1198  return false;
1199  default:
1200  return false;
1201  }
1202 
1203  plan->async_capable = true;
1204 
1205  return true;
1206 }
1207 
1208 /*
1209  * create_append_plan
1210  * Create an Append plan for 'best_path' and (recursively) plans
1211  * for its subpaths.
1212  *
1213  * Returns a Plan node.
1214  */
1215 static Plan *
1217 {
1218  Append *plan;
1219  List *tlist = build_path_tlist(root, &best_path->path);
1220  int orig_tlist_length = list_length(tlist);
1221  bool tlist_was_changed = false;
1222  List *pathkeys = best_path->path.pathkeys;
1223  List *subplans = NIL;
1224  ListCell *subpaths;
1225  int nasyncplans = 0;
1226  RelOptInfo *rel = best_path->path.parent;
1227  PartitionPruneInfo *partpruneinfo = NULL;
1228  int nodenumsortkeys = 0;
1229  AttrNumber *nodeSortColIdx = NULL;
1230  Oid *nodeSortOperators = NULL;
1231  Oid *nodeCollations = NULL;
1232  bool *nodeNullsFirst = NULL;
1233  bool consider_async = false;
1234 
1235  /*
1236  * The subpaths list could be empty, if every child was proven empty by
1237  * constraint exclusion. In that case generate a dummy plan that returns
1238  * no rows.
1239  *
1240  * Note that an AppendPath with no members is also generated in certain
1241  * cases where there was no appending construct at all, but we know the
1242  * relation is empty (see set_dummy_rel_pathlist and mark_dummy_rel).
1243  */
1244  if (best_path->subpaths == NIL)
1245  {
1246  /* Generate a Result plan with constant-FALSE gating qual */
1247  Plan *plan;
1248 
1249  plan = (Plan *) make_result(tlist,
1250  (Node *) list_make1(makeBoolConst(false,
1251  false)),
1252  NULL);
1253 
1254  copy_generic_path_info(plan, (Path *) best_path);
1255 
1256  return plan;
1257  }
1258 
1259  /*
1260  * Otherwise build an Append plan. Note that if there's just one child,
1261  * the Append is pretty useless; but we wait till setrefs.c to get rid of
1262  * it. Doing so here doesn't work because the varno of the child scan
1263  * plan won't match the parent-rel Vars it'll be asked to emit.
1264  *
1265  * We don't have the actual creation of the Append node split out into a
1266  * separate make_xxx function. This is because we want to run
1267  * prepare_sort_from_pathkeys on it before we do so on the individual
1268  * child plans, to make cross-checking the sort info easier.
1269  */
1270  plan = makeNode(Append);
1271  plan->plan.targetlist = tlist;
1272  plan->plan.qual = NIL;
1273  plan->plan.lefttree = NULL;
1274  plan->plan.righttree = NULL;
1275  plan->apprelids = rel->relids;
1276 
1277  if (pathkeys != NIL)
1278  {
1279  /*
1280  * Compute sort column info, and adjust the Append's tlist as needed.
1281  * Because we pass adjust_tlist_in_place = true, we may ignore the
1282  * function result; it must be the same plan node. However, we then
1283  * need to detect whether any tlist entries were added.
1284  */
1285  (void) prepare_sort_from_pathkeys((Plan *) plan, pathkeys,
1286  best_path->path.parent->relids,
1287  NULL,
1288  true,
1289  &nodenumsortkeys,
1290  &nodeSortColIdx,
1291  &nodeSortOperators,
1292  &nodeCollations,
1293  &nodeNullsFirst);
1294  tlist_was_changed = (orig_tlist_length != list_length(plan->plan.targetlist));
1295  }
1296 
1297  /* If appropriate, consider async append */
1298  consider_async = (enable_async_append && pathkeys == NIL &&
1299  !best_path->path.parallel_safe &&
1300  list_length(best_path->subpaths) > 1);
1301 
1302  /* Build the plan for each child */
1303  foreach(subpaths, best_path->subpaths)
1304  {
1305  Path *subpath = (Path *) lfirst(subpaths);
1306  Plan *subplan;
1307 
1308  /* Must insist that all children return the same tlist */
1310 
1311  /*
1312  * For ordered Appends, we must insert a Sort node if subplan isn't
1313  * sufficiently ordered.
1314  */
1315  if (pathkeys != NIL)
1316  {
1317  int numsortkeys;
1318  AttrNumber *sortColIdx;
1319  Oid *sortOperators;
1320  Oid *collations;
1321  bool *nullsFirst;
1322 
1323  /*
1324  * Compute sort column info, and adjust subplan's tlist as needed.
1325  * We must apply prepare_sort_from_pathkeys even to subplans that
1326  * don't need an explicit sort, to make sure they are returning
1327  * the same sort key columns the Append expects.
1328  */
1329  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1330  subpath->parent->relids,
1331  nodeSortColIdx,
1332  false,
1333  &numsortkeys,
1334  &sortColIdx,
1335  &sortOperators,
1336  &collations,
1337  &nullsFirst);
1338 
1339  /*
1340  * Check that we got the same sort key information. We just
1341  * Assert that the sortops match, since those depend only on the
1342  * pathkeys; but it seems like a good idea to check the sort
1343  * column numbers explicitly, to ensure the tlists match up.
1344  */
1345  Assert(numsortkeys == nodenumsortkeys);
1346  if (memcmp(sortColIdx, nodeSortColIdx,
1347  numsortkeys * sizeof(AttrNumber)) != 0)
1348  elog(ERROR, "Append child's targetlist doesn't match Append");
1349  Assert(memcmp(sortOperators, nodeSortOperators,
1350  numsortkeys * sizeof(Oid)) == 0);
1351  Assert(memcmp(collations, nodeCollations,
1352  numsortkeys * sizeof(Oid)) == 0);
1353  Assert(memcmp(nullsFirst, nodeNullsFirst,
1354  numsortkeys * sizeof(bool)) == 0);
1355 
1356  /* Now, insert a Sort node if subplan isn't sufficiently ordered */
1357  if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
1358  {
1359  Sort *sort = make_sort(subplan, numsortkeys,
1360  sortColIdx, sortOperators,
1361  collations, nullsFirst);
1362 
1364  subplan = (Plan *) sort;
1365  }
1366  }
1367 
1368  /* If needed, check to see if subplan can be executed asynchronously */
1369  if (consider_async && mark_async_capable_plan(subplan, subpath))
1370  {
1371  Assert(subplan->async_capable);
1372  ++nasyncplans;
1373  }
1374 
1375  subplans = lappend(subplans, subplan);
1376  }
1377 
1378  /*
1379  * If any quals exist, they may be useful to perform further partition
1380  * pruning during execution. Gather information needed by the executor to
1381  * do partition pruning.
1382  */
1384  {
1385  List *prunequal;
1386 
1387  prunequal = extract_actual_clauses(rel->baserestrictinfo, false);
1388 
1389  if (best_path->path.param_info)
1390  {
1391  List *prmquals = best_path->path.param_info->ppi_clauses;
1392 
1393  prmquals = extract_actual_clauses(prmquals, false);
1394  prmquals = (List *) replace_nestloop_params(root,
1395  (Node *) prmquals);
1396 
1397  prunequal = list_concat(prunequal, prmquals);
1398  }
1399 
1400  if (prunequal != NIL)
1401  partpruneinfo =
1403  best_path->subpaths,
1404  prunequal);
1405  }
1406 
1407  plan->appendplans = subplans;
1408  plan->nasyncplans = nasyncplans;
1409  plan->first_partial_plan = best_path->first_partial_path;
1410  plan->part_prune_info = partpruneinfo;
1411 
1412  copy_generic_path_info(&plan->plan, (Path *) best_path);
1413 
1414  /*
1415  * If prepare_sort_from_pathkeys added sort columns, but we were told to
1416  * produce either the exact tlist or a narrow tlist, we should get rid of
1417  * the sort columns again. We must inject a projection node to do so.
1418  */
1419  if (tlist_was_changed && (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST)))
1420  {
1421  tlist = list_copy_head(plan->plan.targetlist, orig_tlist_length);
1422  return inject_projection_plan((Plan *) plan, tlist,
1423  plan->plan.parallel_safe);
1424  }
1425  else
1426  return (Plan *) plan;
1427 }
1428 
1429 /*
1430  * create_merge_append_plan
1431  * Create a MergeAppend plan for 'best_path' and (recursively) plans
1432  * for its subpaths.
1433  *
1434  * Returns a Plan node.
1435  */
1436 static Plan *
1438  int flags)
1439 {
1440  MergeAppend *node = makeNode(MergeAppend);
1441  Plan *plan = &node->plan;
1442  List *tlist = build_path_tlist(root, &best_path->path);
1443  int orig_tlist_length = list_length(tlist);
1444  bool tlist_was_changed;
1445  List *pathkeys = best_path->path.pathkeys;
1446  List *subplans = NIL;
1447  ListCell *subpaths;
1448  RelOptInfo *rel = best_path->path.parent;
1449  PartitionPruneInfo *partpruneinfo = NULL;
1450 
1451  /*
1452  * We don't have the actual creation of the MergeAppend node split out
1453  * into a separate make_xxx function. This is because we want to run
1454  * prepare_sort_from_pathkeys on it before we do so on the individual
1455  * child plans, to make cross-checking the sort info easier.
1456  */
1457  copy_generic_path_info(plan, (Path *) best_path);
1458  plan->targetlist = tlist;
1459  plan->qual = NIL;
1460  plan->lefttree = NULL;
1461  plan->righttree = NULL;
1462  node->apprelids = rel->relids;
1463 
1464  /*
1465  * Compute sort column info, and adjust MergeAppend's tlist as needed.
1466  * Because we pass adjust_tlist_in_place = true, we may ignore the
1467  * function result; it must be the same plan node. However, we then need
1468  * to detect whether any tlist entries were added.
1469  */
1470  (void) prepare_sort_from_pathkeys(plan, pathkeys,
1471  best_path->path.parent->relids,
1472  NULL,
1473  true,
1474  &node->numCols,
1475  &node->sortColIdx,
1476  &node->sortOperators,
1477  &node->collations,
1478  &node->nullsFirst);
1479  tlist_was_changed = (orig_tlist_length != list_length(plan->targetlist));
1480 
1481  /*
1482  * Now prepare the child plans. We must apply prepare_sort_from_pathkeys
1483  * even to subplans that don't need an explicit sort, to make sure they
1484  * are returning the same sort key columns the MergeAppend expects.
1485  */
1486  foreach(subpaths, best_path->subpaths)
1487  {
1488  Path *subpath = (Path *) lfirst(subpaths);
1489  Plan *subplan;
1490  int numsortkeys;
1491  AttrNumber *sortColIdx;
1492  Oid *sortOperators;
1493  Oid *collations;
1494  bool *nullsFirst;
1495 
1496  /* Build the child plan */
1497  /* Must insist that all children return the same tlist */
1499 
1500  /* Compute sort column info, and adjust subplan's tlist as needed */
1501  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1502  subpath->parent->relids,
1503  node->sortColIdx,
1504  false,
1505  &numsortkeys,
1506  &sortColIdx,
1507  &sortOperators,
1508  &collations,
1509  &nullsFirst);
1510 
1511  /*
1512  * Check that we got the same sort key information. We just Assert
1513  * that the sortops match, since those depend only on the pathkeys;
1514  * but it seems like a good idea to check the sort column numbers
1515  * explicitly, to ensure the tlists really do match up.
1516  */
1517  Assert(numsortkeys == node->numCols);
1518  if (memcmp(sortColIdx, node->sortColIdx,
1519  numsortkeys * sizeof(AttrNumber)) != 0)
1520  elog(ERROR, "MergeAppend child's targetlist doesn't match MergeAppend");
1521  Assert(memcmp(sortOperators, node->sortOperators,
1522  numsortkeys * sizeof(Oid)) == 0);
1523  Assert(memcmp(collations, node->collations,
1524  numsortkeys * sizeof(Oid)) == 0);
1525  Assert(memcmp(nullsFirst, node->nullsFirst,
1526  numsortkeys * sizeof(bool)) == 0);
1527 
1528  /* Now, insert a Sort node if subplan isn't sufficiently ordered */
1529  if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
1530  {
1531  Sort *sort = make_sort(subplan, numsortkeys,
1532  sortColIdx, sortOperators,
1533  collations, nullsFirst);
1534 
1536  subplan = (Plan *) sort;
1537  }
1538 
1539  subplans = lappend(subplans, subplan);
1540  }
1541 
1542  /*
1543  * If any quals exist, they may be useful to perform further partition
1544  * pruning during execution. Gather information needed by the executor to
1545  * do partition pruning.
1546  */
1548  {
1549  List *prunequal;
1550 
1551  prunequal = extract_actual_clauses(rel->baserestrictinfo, false);
1552 
1553  /* We don't currently generate any parameterized MergeAppend paths */
1554  Assert(best_path->path.param_info == NULL);
1555 
1556  if (prunequal != NIL)
1557  partpruneinfo = make_partition_pruneinfo(root, rel,
1558  best_path->subpaths,
1559  prunequal);
1560  }
1561 
1562  node->mergeplans = subplans;
1563  node->part_prune_info = partpruneinfo;
1564 
1565  /*
1566  * If prepare_sort_from_pathkeys added sort columns, but we were told to
1567  * produce either the exact tlist or a narrow tlist, we should get rid of
1568  * the sort columns again. We must inject a projection node to do so.
1569  */
1570  if (tlist_was_changed && (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST)))
1571  {
1572  tlist = list_copy_head(plan->targetlist, orig_tlist_length);
1573  return inject_projection_plan(plan, tlist, plan->parallel_safe);
1574  }
1575  else
1576  return plan;
1577 }
1578 
1579 /*
1580  * create_group_result_plan
1581  * Create a Result plan for 'best_path'.
1582  * This is only used for degenerate grouping cases.
1583  *
1584  * Returns a Plan node.
1585  */
1586 static Result *
1588 {
1589  Result *plan;
1590  List *tlist;
1591  List *quals;
1592 
1593  tlist = build_path_tlist(root, &best_path->path);
1594 
1595  /* best_path->quals is just bare clauses */
1596  quals = order_qual_clauses(root, best_path->quals);
1597 
1598  plan = make_result(tlist, (Node *) quals, NULL);
1599 
1600  copy_generic_path_info(&plan->plan, (Path *) best_path);
1601 
1602  return plan;
1603 }
1604 
1605 /*
1606  * create_project_set_plan
1607  * Create a ProjectSet plan for 'best_path'.
1608  *
1609  * Returns a Plan node.
1610  */
1611 static ProjectSet *
1613 {
1614  ProjectSet *plan;
1615  Plan *subplan;
1616  List *tlist;
1617 
1618  /* Since we intend to project, we don't need to constrain child tlist */
1619  subplan = create_plan_recurse(root, best_path->subpath, 0);
1620 
1621  tlist = build_path_tlist(root, &best_path->path);
1622 
1623  plan = make_project_set(tlist, subplan);
1624 
1625  copy_generic_path_info(&plan->plan, (Path *) best_path);
1626 
1627  return plan;
1628 }
1629 
1630 /*
1631  * create_material_plan
1632  * Create a Material plan for 'best_path' and (recursively) plans
1633  * for its subpaths.
1634  *
1635  * Returns a Plan node.
1636  */
1637 static Material *
1639 {
1640  Material *plan;
1641  Plan *subplan;
1642 
1643  /*
1644  * We don't want any excess columns in the materialized tuples, so request
1645  * a smaller tlist. Otherwise, since Material doesn't project, tlist
1646  * requirements pass through.
1647  */
1648  subplan = create_plan_recurse(root, best_path->subpath,
1649  flags | CP_SMALL_TLIST);
1650 
1651  plan = make_material(subplan);
1652 
1653  copy_generic_path_info(&plan->plan, (Path *) best_path);
1654 
1655  return plan;
1656 }
1657 
1658 /*
1659  * create_memoize_plan
1660  * Create a Memoize plan for 'best_path' and (recursively) plans for its
1661  * subpaths.
1662  *
1663  * Returns a Plan node.
1664  */
1665 static Memoize *
1667 {
1668  Memoize *plan;
1669  Bitmapset *keyparamids;
1670  Plan *subplan;
1671  Oid *operators;
1672  Oid *collations;
1673  List *param_exprs = NIL;
1674  ListCell *lc;
1675  ListCell *lc2;
1676  int nkeys;
1677  int i;
1678 
1679  subplan = create_plan_recurse(root, best_path->subpath,
1680  flags | CP_SMALL_TLIST);
1681 
1682  param_exprs = (List *) replace_nestloop_params(root, (Node *)
1683  best_path->param_exprs);
1684 
1685  nkeys = list_length(param_exprs);
1686  Assert(nkeys > 0);
1687  operators = palloc(nkeys * sizeof(Oid));
1688  collations = palloc(nkeys * sizeof(Oid));
1689 
1690  i = 0;
1691  forboth(lc, param_exprs, lc2, best_path->hash_operators)
1692  {
1693  Expr *param_expr = (Expr *) lfirst(lc);
1694  Oid opno = lfirst_oid(lc2);
1695 
1696  operators[i] = opno;
1697  collations[i] = exprCollation((Node *) param_expr);
1698  i++;
1699  }
1700 
1701  keyparamids = pull_paramids((Expr *) param_exprs);
1702 
1703  plan = make_memoize(subplan, operators, collations, param_exprs,
1704  best_path->singlerow, best_path->binary_mode,
1705  best_path->est_entries, keyparamids);
1706 
1707  copy_generic_path_info(&plan->plan, (Path *) best_path);
1708 
1709  return plan;
1710 }
1711 
1712 /*
1713  * create_unique_plan
1714  * Create a Unique plan for 'best_path' and (recursively) plans
1715  * for its subpaths.
1716  *
1717  * Returns a Plan node.
1718  */
1719 static Plan *
1721 {
1722  Plan *plan;
1723  Plan *subplan;
1724  List *in_operators;
1725  List *uniq_exprs;
1726  List *newtlist;
1727  int nextresno;
1728  bool newitems;
1729  int numGroupCols;
1730  AttrNumber *groupColIdx;
1731  Oid *groupCollations;
1732  int groupColPos;
1733  ListCell *l;
1734 
1735  /* Unique doesn't project, so tlist requirements pass through */
1736  subplan = create_plan_recurse(root, best_path->subpath, flags);
1737 
1738  /* Done if we don't need to do any actual unique-ifying */
1739  if (best_path->umethod == UNIQUE_PATH_NOOP)
1740  return subplan;
1741 
1742  /*
1743  * As constructed, the subplan has a "flat" tlist containing just the Vars
1744  * needed here and at upper levels. The values we are supposed to
1745  * unique-ify may be expressions in these variables. We have to add any
1746  * such expressions to the subplan's tlist.
1747  *
1748  * The subplan may have a "physical" tlist if it is a simple scan plan. If
1749  * we're going to sort, this should be reduced to the regular tlist, so
1750  * that we don't sort more data than we need to. For hashing, the tlist
1751  * should be left as-is if we don't need to add any expressions; but if we
1752  * do have to add expressions, then a projection step will be needed at
1753  * runtime anyway, so we may as well remove unneeded items. Therefore
1754  * newtlist starts from build_path_tlist() not just a copy of the
1755  * subplan's tlist; and we don't install it into the subplan unless we are
1756  * sorting or stuff has to be added.
1757  */
1758  in_operators = best_path->in_operators;
1759  uniq_exprs = best_path->uniq_exprs;
1760 
1761  /* initialize modified subplan tlist as just the "required" vars */
1762  newtlist = build_path_tlist(root, &best_path->path);
1763  nextresno = list_length(newtlist) + 1;
1764  newitems = false;
1765 
1766  foreach(l, uniq_exprs)
1767  {
1768  Expr *uniqexpr = lfirst(l);
1769  TargetEntry *tle;
1770 
1771  tle = tlist_member(uniqexpr, newtlist);
1772  if (!tle)
1773  {
1774  tle = makeTargetEntry((Expr *) uniqexpr,
1775  nextresno,
1776  NULL,
1777  false);
1778  newtlist = lappend(newtlist, tle);
1779  nextresno++;
1780  newitems = true;
1781  }
1782  }
1783 
1784  /* Use change_plan_targetlist in case we need to insert a Result node */
1785  if (newitems || best_path->umethod == UNIQUE_PATH_SORT)
1786  subplan = change_plan_targetlist(subplan, newtlist,
1787  best_path->path.parallel_safe);
1788 
1789  /*
1790  * Build control information showing which subplan output columns are to
1791  * be examined by the grouping step. Unfortunately we can't merge this
1792  * with the previous loop, since we didn't then know which version of the
1793  * subplan tlist we'd end up using.
1794  */
1795  newtlist = subplan->targetlist;
1796  numGroupCols = list_length(uniq_exprs);
1797  groupColIdx = (AttrNumber *) palloc(numGroupCols * sizeof(AttrNumber));
1798  groupCollations = (Oid *) palloc(numGroupCols * sizeof(Oid));
1799 
1800  groupColPos = 0;
1801  foreach(l, uniq_exprs)
1802  {
1803  Expr *uniqexpr = lfirst(l);
1804  TargetEntry *tle;
1805 
1806  tle = tlist_member(uniqexpr, newtlist);
1807  if (!tle) /* shouldn't happen */
1808  elog(ERROR, "failed to find unique expression in subplan tlist");
1809  groupColIdx[groupColPos] = tle->resno;
1810  groupCollations[groupColPos] = exprCollation((Node *) tle->expr);
1811  groupColPos++;
1812  }
1813 
1814  if (best_path->umethod == UNIQUE_PATH_HASH)
1815  {
1816  Oid *groupOperators;
1817 
1818  /*
1819  * Get the hashable equality operators for the Agg node to use.
1820  * Normally these are the same as the IN clause operators, but if
1821  * those are cross-type operators then the equality operators are the
1822  * ones for the IN clause operators' RHS datatype.
1823  */
1824  groupOperators = (Oid *) palloc(numGroupCols * sizeof(Oid));
1825  groupColPos = 0;
1826  foreach(l, in_operators)
1827  {
1828  Oid in_oper = lfirst_oid(l);
1829  Oid eq_oper;
1830 
1831  if (!get_compatible_hash_operators(in_oper, NULL, &eq_oper))
1832  elog(ERROR, "could not find compatible hash operator for operator %u",
1833  in_oper);
1834  groupOperators[groupColPos++] = eq_oper;
1835  }
1836 
1837  /*
1838  * Since the Agg node is going to project anyway, we can give it the
1839  * minimum output tlist, without any stuff we might have added to the
1840  * subplan tlist.
1841  */
1842  plan = (Plan *) make_agg(build_path_tlist(root, &best_path->path),
1843  NIL,
1844  AGG_HASHED,
1846  numGroupCols,
1847  groupColIdx,
1848  groupOperators,
1849  groupCollations,
1850  NIL,
1851  NIL,
1852  best_path->path.rows,
1853  0,
1854  subplan);
1855  }
1856  else
1857  {
1858  List *sortList = NIL;
1859  Sort *sort;
1860 
1861  /* Create an ORDER BY list to sort the input compatibly */
1862  groupColPos = 0;
1863  foreach(l, in_operators)
1864  {
1865  Oid in_oper = lfirst_oid(l);
1866  Oid sortop;
1867  Oid eqop;
1868  TargetEntry *tle;
1869  SortGroupClause *sortcl;
1870 
1871  sortop = get_ordering_op_for_equality_op(in_oper, false);
1872  if (!OidIsValid(sortop)) /* shouldn't happen */
1873  elog(ERROR, "could not find ordering operator for equality operator %u",
1874  in_oper);
1875 
1876  /*
1877  * The Unique node will need equality operators. Normally these
1878  * are the same as the IN clause operators, but if those are
1879  * cross-type operators then the equality operators are the ones
1880  * for the IN clause operators' RHS datatype.
1881  */
1882  eqop = get_equality_op_for_ordering_op(sortop, NULL);
1883  if (!OidIsValid(eqop)) /* shouldn't happen */
1884  elog(ERROR, "could not find equality operator for ordering operator %u",
1885  sortop);
1886 
1887  tle = get_tle_by_resno(subplan->targetlist,
1888  groupColIdx[groupColPos]);
1889  Assert(tle != NULL);
1890 
1891  sortcl = makeNode(SortGroupClause);
1892  sortcl->tleSortGroupRef = assignSortGroupRef(tle,
1893  subplan->targetlist);
1894  sortcl->eqop = eqop;
1895  sortcl->sortop = sortop;
1896  sortcl->nulls_first = false;
1897  sortcl->hashable = false; /* no need to make this accurate */
1898  sortList = lappend(sortList, sortcl);
1899  groupColPos++;
1900  }
1901  sort = make_sort_from_sortclauses(sortList, subplan);
1903  plan = (Plan *) make_unique_from_sortclauses((Plan *) sort, sortList);
1904  }
1905 
1906  /* Copy cost data from Path to Plan */
1907  copy_generic_path_info(plan, &best_path->path);
1908 
1909  return plan;
1910 }
1911 
1912 /*
1913  * create_gather_plan
1914  *
1915  * Create a Gather plan for 'best_path' and (recursively) plans
1916  * for its subpaths.
1917  */
1918 static Gather *
1920 {
1921  Gather *gather_plan;
1922  Plan *subplan;
1923  List *tlist;
1924 
1925  /*
1926  * Push projection down to the child node. That way, the projection work
1927  * is parallelized, and there can be no system columns in the result (they
1928  * can't travel through a tuple queue because it uses MinimalTuple
1929  * representation).
1930  */
1931  subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
1932 
1933  tlist = build_path_tlist(root, &best_path->path);
1934 
1935  gather_plan = make_gather(tlist,
1936  NIL,
1937  best_path->num_workers,
1939  best_path->single_copy,
1940  subplan);
1941 
1942  copy_generic_path_info(&gather_plan->plan, &best_path->path);
1943 
1944  /* use parallel mode for parallel plans. */
1945  root->glob->parallelModeNeeded = true;
1946 
1947  return gather_plan;
1948 }
1949 
1950 /*
1951  * create_gather_merge_plan
1952  *
1953  * Create a Gather Merge plan for 'best_path' and (recursively)
1954  * plans for its subpaths.
1955  */
1956 static GatherMerge *
1958 {
1959  GatherMerge *gm_plan;
1960  Plan *subplan;
1961  List *pathkeys = best_path->path.pathkeys;
1962  List *tlist = build_path_tlist(root, &best_path->path);
1963 
1964  /* As with Gather, project away columns in the workers. */
1965  subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
1966 
1967  /* Create a shell for a GatherMerge plan. */
1968  gm_plan = makeNode(GatherMerge);
1969  gm_plan->plan.targetlist = tlist;
1970  gm_plan->num_workers = best_path->num_workers;
1971  copy_generic_path_info(&gm_plan->plan, &best_path->path);
1972 
1973  /* Assign the rescan Param. */
1975 
1976  /* Gather Merge is pointless with no pathkeys; use Gather instead. */
1977  Assert(pathkeys != NIL);
1978 
1979  /* Compute sort column info, and adjust subplan's tlist as needed */
1980  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1981  best_path->subpath->parent->relids,
1982  gm_plan->sortColIdx,
1983  false,
1984  &gm_plan->numCols,
1985  &gm_plan->sortColIdx,
1986  &gm_plan->sortOperators,
1987  &gm_plan->collations,
1988  &gm_plan->nullsFirst);
1989 
1990 
1991  /*
1992  * All gather merge paths should have already guaranteed the necessary
1993  * sort order either by adding an explicit sort node or by using presorted
1994  * input. We can't simply add a sort here on additional pathkeys, because
1995  * we can't guarantee the sort would be safe. For example, expressions may
1996  * be volatile or otherwise parallel unsafe.
1997  */
1998  if (!pathkeys_contained_in(pathkeys, best_path->subpath->pathkeys))
1999  elog(ERROR, "gather merge input not sufficiently sorted");
2000 
2001  /* Now insert the subplan under GatherMerge. */
2002  gm_plan->plan.lefttree = subplan;
2003 
2004  /* use parallel mode for parallel plans. */
2005  root->glob->parallelModeNeeded = true;
2006 
2007  return gm_plan;
2008 }
2009 
2010 /*
2011  * create_projection_plan
2012  *
2013  * Create a plan tree to do a projection step and (recursively) plans
2014  * for its subpaths. We may need a Result node for the projection,
2015  * but sometimes we can just let the subplan do the work.
2016  */
2017 static Plan *
2019 {
2020  Plan *plan;
2021  Plan *subplan;
2022  List *tlist;
2023  bool needs_result_node = false;
2024 
2025  /*
2026  * Convert our subpath to a Plan and determine whether we need a Result
2027  * node.
2028  *
2029  * In most cases where we don't need to project, creation_projection_path
2030  * will have set dummypp, but not always. First, some createplan.c
2031  * routines change the tlists of their nodes. (An example is that
2032  * create_merge_append_plan might add resjunk sort columns to a
2033  * MergeAppend.) Second, create_projection_path has no way of knowing
2034  * what path node will be placed on top of the projection path and
2035  * therefore can't predict whether it will require an exact tlist. For
2036  * both of these reasons, we have to recheck here.
2037  */
2038  if (use_physical_tlist(root, &best_path->path, flags))
2039  {
2040  /*
2041  * Our caller doesn't really care what tlist we return, so we don't
2042  * actually need to project. However, we may still need to ensure
2043  * proper sortgroupref labels, if the caller cares about those.
2044  */
2045  subplan = create_plan_recurse(root, best_path->subpath, 0);
2046  tlist = subplan->targetlist;
2047  if (flags & CP_LABEL_TLIST)
2049  best_path->path.pathtarget);
2050  }
2051  else if (is_projection_capable_path(best_path->subpath))
2052  {
2053  /*
2054  * Our caller requires that we return the exact tlist, but no separate
2055  * result node is needed because the subpath is projection-capable.
2056  * Tell create_plan_recurse that we're going to ignore the tlist it
2057  * produces.
2058  */
2059  subplan = create_plan_recurse(root, best_path->subpath,
2060  CP_IGNORE_TLIST);
2062  tlist = build_path_tlist(root, &best_path->path);
2063  }
2064  else
2065  {
2066  /*
2067  * It looks like we need a result node, unless by good fortune the
2068  * requested tlist is exactly the one the child wants to produce.
2069  */
2070  subplan = create_plan_recurse(root, best_path->subpath, 0);
2071  tlist = build_path_tlist(root, &best_path->path);
2072  needs_result_node = !tlist_same_exprs(tlist, subplan->targetlist);
2073  }
2074 
2075  /*
2076  * If we make a different decision about whether to include a Result node
2077  * than create_projection_path did, we'll have made slightly wrong cost
2078  * estimates; but label the plan with the cost estimates we actually used,
2079  * not "corrected" ones. (XXX this could be cleaned up if we moved more
2080  * of the sortcolumn setup logic into Path creation, but that would add
2081  * expense to creating Paths we might end up not using.)
2082  */
2083  if (!needs_result_node)
2084  {
2085  /* Don't need a separate Result, just assign tlist to subplan */
2086  plan = subplan;
2087  plan->targetlist = tlist;
2088 
2089  /* Label plan with the estimated costs we actually used */
2090  plan->startup_cost = best_path->path.startup_cost;
2091  plan->total_cost = best_path->path.total_cost;
2092  plan->plan_rows = best_path->path.rows;
2093  plan->plan_width = best_path->path.pathtarget->width;
2094  plan->parallel_safe = best_path->path.parallel_safe;
2095  /* ... but don't change subplan's parallel_aware flag */
2096  }
2097  else
2098  {
2099  /* We need a Result node */
2100  plan = (Plan *) make_result(tlist, NULL, subplan);
2101 
2102  copy_generic_path_info(plan, (Path *) best_path);
2103  }
2104 
2105  return plan;
2106 }
2107 
2108 /*
2109  * inject_projection_plan
2110  * Insert a Result node to do a projection step.
2111  *
2112  * This is used in a few places where we decide on-the-fly that we need a
2113  * projection step as part of the tree generated for some Path node.
2114  * We should try to get rid of this in favor of doing it more honestly.
2115  *
2116  * One reason it's ugly is we have to be told the right parallel_safe marking
2117  * to apply (since the tlist might be unsafe even if the child plan is safe).
2118  */
2119 static Plan *
2120 inject_projection_plan(Plan *subplan, List *tlist, bool parallel_safe)
2121 {
2122  Plan *plan;
2123 
2124  plan = (Plan *) make_result(tlist, NULL, subplan);
2125 
2126  /*
2127  * In principle, we should charge tlist eval cost plus cpu_per_tuple per
2128  * row for the Result node. But the former has probably been factored in
2129  * already and the latter was not accounted for during Path construction,
2130  * so being formally correct might just make the EXPLAIN output look less
2131  * consistent not more so. Hence, just copy the subplan's cost.
2132  */
2133  copy_plan_costsize(plan, subplan);
2134  plan->parallel_safe = parallel_safe;
2135 
2136  return plan;
2137 }
2138 
2139 /*
2140  * change_plan_targetlist
2141  * Externally available wrapper for inject_projection_plan.
2142  *
2143  * This is meant for use by FDW plan-generation functions, which might
2144  * want to adjust the tlist computed by some subplan tree. In general,
2145  * a Result node is needed to compute the new tlist, but we can optimize
2146  * some cases.
2147  *
2148  * In most cases, tlist_parallel_safe can just be passed as the parallel_safe
2149  * flag of the FDW's own Path node.
2150  */
2151 Plan *
2152 change_plan_targetlist(Plan *subplan, List *tlist, bool tlist_parallel_safe)
2153 {
2154  /*
2155  * If the top plan node can't do projections and its existing target list
2156  * isn't already what we need, we need to add a Result node to help it
2157  * along.
2158  */
2159  if (!is_projection_capable_plan(subplan) &&
2160  !tlist_same_exprs(tlist, subplan->targetlist))
2161  subplan = inject_projection_plan(subplan, tlist,
2162  subplan->parallel_safe &&
2163  tlist_parallel_safe);
2164  else
2165  {
2166  /* Else we can just replace the plan node's tlist */
2167  subplan->targetlist = tlist;
2168  subplan->parallel_safe &= tlist_parallel_safe;
2169  }
2170  return subplan;
2171 }
2172 
2173 /*
2174  * create_sort_plan
2175  *
2176  * Create a Sort plan for 'best_path' and (recursively) plans
2177  * for its subpaths.
2178  */
2179 static Sort *
2180 create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags)
2181 {
2182  Sort *plan;
2183  Plan *subplan;
2184 
2185  /*
2186  * We don't want any excess columns in the sorted tuples, so request a
2187  * smaller tlist. Otherwise, since Sort doesn't project, tlist
2188  * requirements pass through.
2189  */
2190  subplan = create_plan_recurse(root, best_path->subpath,
2191  flags | CP_SMALL_TLIST);
2192 
2193  /*
2194  * make_sort_from_pathkeys indirectly calls find_ec_member_matching_expr,
2195  * which will ignore any child EC members that don't belong to the given
2196  * relids. Thus, if this sort path is based on a child relation, we must
2197  * pass its relids.
2198  */
2199  plan = make_sort_from_pathkeys(subplan, best_path->path.pathkeys,
2200  IS_OTHER_REL(best_path->subpath->parent) ?
2201  best_path->path.parent->relids : NULL);
2202 
2203  copy_generic_path_info(&plan->plan, (Path *) best_path);
2204 
2205  return plan;
2206 }
2207 
2208 /*
2209  * create_incrementalsort_plan
2210  *
2211  * Do the same as create_sort_plan, but create IncrementalSort plan.
2212  */
2213 static IncrementalSort *
2215  int flags)
2216 {
2218  Plan *subplan;
2219 
2220  /* See comments in create_sort_plan() above */
2221  subplan = create_plan_recurse(root, best_path->spath.subpath,
2222  flags | CP_SMALL_TLIST);
2224  best_path->spath.path.pathkeys,
2225  IS_OTHER_REL(best_path->spath.subpath->parent) ?
2226  best_path->spath.path.parent->relids : NULL,
2227  best_path->nPresortedCols);
2228 
2229  copy_generic_path_info(&plan->sort.plan, (Path *) best_path);
2230 
2231  return plan;
2232 }
2233 
2234 /*
2235  * create_group_plan
2236  *
2237  * Create a Group plan for 'best_path' and (recursively) plans
2238  * for its subpaths.
2239  */
2240 static Group *
2242 {
2243  Group *plan;
2244  Plan *subplan;
2245  List *tlist;
2246  List *quals;
2247 
2248  /*
2249  * Group can project, so no need to be terribly picky about child tlist,
2250  * but we do need grouping columns to be available
2251  */
2252  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2253 
2254  tlist = build_path_tlist(root, &best_path->path);
2255 
2256  quals = order_qual_clauses(root, best_path->qual);
2257 
2258  plan = make_group(tlist,
2259  quals,
2260  list_length(best_path->groupClause),
2262  subplan->targetlist),
2263  extract_grouping_ops(best_path->groupClause),
2265  subplan->targetlist),
2266  subplan);
2267 
2268  copy_generic_path_info(&plan->plan, (Path *) best_path);
2269 
2270  return plan;
2271 }
2272 
2273 /*
2274  * create_upper_unique_plan
2275  *
2276  * Create a Unique plan for 'best_path' and (recursively) plans
2277  * for its subpaths.
2278  */
2279 static Unique *
2281 {
2282  Unique *plan;
2283  Plan *subplan;
2284 
2285  /*
2286  * Unique doesn't project, so tlist requirements pass through; moreover we
2287  * need grouping columns to be labeled.
2288  */
2289  subplan = create_plan_recurse(root, best_path->subpath,
2290  flags | CP_LABEL_TLIST);
2291 
2292  plan = make_unique_from_pathkeys(subplan,
2293  best_path->path.pathkeys,
2294  best_path->numkeys);
2295 
2296  copy_generic_path_info(&plan->plan, (Path *) best_path);
2297 
2298  return plan;
2299 }
2300 
2301 /*
2302  * create_agg_plan
2303  *
2304  * Create an Agg plan for 'best_path' and (recursively) plans
2305  * for its subpaths.
2306  */
2307 static Agg *
2309 {
2310  Agg *plan;
2311  Plan *subplan;
2312  List *tlist;
2313  List *quals;
2314 
2315  /*
2316  * Agg can project, so no need to be terribly picky about child tlist, but
2317  * we do need grouping columns to be available
2318  */
2319  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2320 
2321  tlist = build_path_tlist(root, &best_path->path);
2322 
2323  quals = order_qual_clauses(root, best_path->qual);
2324 
2325  plan = make_agg(tlist, quals,
2326  best_path->aggstrategy,
2327  best_path->aggsplit,
2328  list_length(best_path->groupClause),
2330  subplan->targetlist),
2331  extract_grouping_ops(best_path->groupClause),
2333  subplan->targetlist),
2334  NIL,
2335  NIL,
2336  best_path->numGroups,
2337  best_path->transitionSpace,
2338  subplan);
2339 
2340  copy_generic_path_info(&plan->plan, (Path *) best_path);
2341 
2342  return plan;
2343 }
2344 
2345 /*
2346  * Given a groupclause for a collection of grouping sets, produce the
2347  * corresponding groupColIdx.
2348  *
2349  * root->grouping_map maps the tleSortGroupRef to the actual column position in
2350  * the input tuple. So we get the ref from the entries in the groupclause and
2351  * look them up there.
2352  */
2353 static AttrNumber *
2355 {
2356  AttrNumber *grouping_map = root->grouping_map;
2357  AttrNumber *new_grpColIdx;
2358  ListCell *lc;
2359  int i;
2360 
2361  Assert(grouping_map);
2362 
2363  new_grpColIdx = palloc0(sizeof(AttrNumber) * list_length(groupClause));
2364 
2365  i = 0;
2366  foreach(lc, groupClause)
2367  {
2368  SortGroupClause *clause = lfirst(lc);
2369 
2370  new_grpColIdx[i++] = grouping_map[clause->tleSortGroupRef];
2371  }
2372 
2373  return new_grpColIdx;
2374 }
2375 
2376 /*
2377  * create_groupingsets_plan
2378  * Create a plan for 'best_path' and (recursively) plans
2379  * for its subpaths.
2380  *
2381  * What we emit is an Agg plan with some vestigial Agg and Sort nodes
2382  * hanging off the side. The top Agg implements the last grouping set
2383  * specified in the GroupingSetsPath, and any additional grouping sets
2384  * each give rise to a subsidiary Agg and Sort node in the top Agg's
2385  * "chain" list. These nodes don't participate in the plan directly,
2386  * but they are a convenient way to represent the required data for
2387  * the extra steps.
2388  *
2389  * Returns a Plan node.
2390  */
2391 static Plan *
2393 {
2394  Agg *plan;
2395  Plan *subplan;
2396  List *rollups = best_path->rollups;
2397  AttrNumber *grouping_map;
2398  int maxref;
2399  List *chain;
2400  ListCell *lc;
2401 
2402  /* Shouldn't get here without grouping sets */
2403  Assert(root->parse->groupingSets);
2404  Assert(rollups != NIL);
2405 
2406  /*
2407  * Agg can project, so no need to be terribly picky about child tlist, but
2408  * we do need grouping columns to be available
2409  */
2410  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2411 
2412  /*
2413  * Compute the mapping from tleSortGroupRef to column index in the child's
2414  * tlist. First, identify max SortGroupRef in groupClause, for array
2415  * sizing.
2416  */
2417  maxref = 0;
2418  foreach(lc, root->processed_groupClause)
2419  {
2420  SortGroupClause *gc = (SortGroupClause *) lfirst(lc);
2421 
2422  if (gc->tleSortGroupRef > maxref)
2423  maxref = gc->tleSortGroupRef;
2424  }
2425 
2426  grouping_map = (AttrNumber *) palloc0((maxref + 1) * sizeof(AttrNumber));
2427 
2428  /* Now look up the column numbers in the child's tlist */
2429  foreach(lc, root->processed_groupClause)
2430  {
2431  SortGroupClause *gc = (SortGroupClause *) lfirst(lc);
2432  TargetEntry *tle = get_sortgroupclause_tle(gc, subplan->targetlist);
2433 
2434  grouping_map[gc->tleSortGroupRef] = tle->resno;
2435  }
2436 
2437  /*
2438  * During setrefs.c, we'll need the grouping_map to fix up the cols lists
2439  * in GroupingFunc nodes. Save it for setrefs.c to use.
2440  */
2441  Assert(root->grouping_map == NULL);
2442  root->grouping_map = grouping_map;
2443 
2444  /*
2445  * Generate the side nodes that describe the other sort and group
2446  * operations besides the top one. Note that we don't worry about putting
2447  * accurate cost estimates in the side nodes; only the topmost Agg node's
2448  * costs will be shown by EXPLAIN.
2449  */
2450  chain = NIL;
2451  if (list_length(rollups) > 1)
2452  {
2453  bool is_first_sort = ((RollupData *) linitial(rollups))->is_hashed;
2454 
2455  for_each_from(lc, rollups, 1)
2456  {
2457  RollupData *rollup = lfirst(lc);
2458  AttrNumber *new_grpColIdx;
2459  Plan *sort_plan = NULL;
2460  Plan *agg_plan;
2461  AggStrategy strat;
2462 
2463  new_grpColIdx = remap_groupColIdx(root, rollup->groupClause);
2464 
2465  if (!rollup->is_hashed && !is_first_sort)
2466  {
2467  sort_plan = (Plan *)
2469  new_grpColIdx,
2470  subplan);
2471  }
2472 
2473  if (!rollup->is_hashed)
2474  is_first_sort = false;
2475 
2476  if (rollup->is_hashed)
2477  strat = AGG_HASHED;
2478  else if (linitial(rollup->gsets) == NIL)
2479  strat = AGG_PLAIN;
2480  else
2481  strat = AGG_SORTED;
2482 
2483  agg_plan = (Plan *) make_agg(NIL,
2484  NIL,
2485  strat,
2487  list_length((List *) linitial(rollup->gsets)),
2488  new_grpColIdx,
2491  rollup->gsets,
2492  NIL,
2493  rollup->numGroups,
2494  best_path->transitionSpace,
2495  sort_plan);
2496 
2497  /*
2498  * Remove stuff we don't need to avoid bloating debug output.
2499  */
2500  if (sort_plan)
2501  {
2502  sort_plan->targetlist = NIL;
2503  sort_plan->lefttree = NULL;
2504  }
2505 
2506  chain = lappend(chain, agg_plan);
2507  }
2508  }
2509 
2510  /*
2511  * Now make the real Agg node
2512  */
2513  {
2514  RollupData *rollup = linitial(rollups);
2515  AttrNumber *top_grpColIdx;
2516  int numGroupCols;
2517 
2518  top_grpColIdx = remap_groupColIdx(root, rollup->groupClause);
2519 
2520  numGroupCols = list_length((List *) linitial(rollup->gsets));
2521 
2522  plan = make_agg(build_path_tlist(root, &best_path->path),
2523  best_path->qual,
2524  best_path->aggstrategy,
2526  numGroupCols,
2527  top_grpColIdx,
2530  rollup->gsets,
2531  chain,
2532  rollup->numGroups,
2533  best_path->transitionSpace,
2534  subplan);
2535 
2536  /* Copy cost data from Path to Plan */
2537  copy_generic_path_info(&plan->plan, &best_path->path);
2538  }
2539 
2540  return (Plan *) plan;
2541 }
2542 
2543 /*
2544  * create_minmaxagg_plan
2545  *
2546  * Create a Result plan for 'best_path' and (recursively) plans
2547  * for its subpaths.
2548  */
2549 static Result *
2551 {
2552  Result *plan;
2553  List *tlist;
2554  ListCell *lc;
2555 
2556  /* Prepare an InitPlan for each aggregate's subquery. */
2557  foreach(lc, best_path->mmaggregates)
2558  {
2559  MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
2560  PlannerInfo *subroot = mminfo->subroot;
2561  Query *subparse = subroot->parse;
2562  Plan *plan;
2563 
2564  /*
2565  * Generate the plan for the subquery. We already have a Path, but we
2566  * have to convert it to a Plan and attach a LIMIT node above it.
2567  * Since we are entering a different planner context (subroot),
2568  * recurse to create_plan not create_plan_recurse.
2569  */
2570  plan = create_plan(subroot, mminfo->path);
2571 
2572  plan = (Plan *) make_limit(plan,
2573  subparse->limitOffset,
2574  subparse->limitCount,
2575  subparse->limitOption,
2576  0, NULL, NULL, NULL);
2577 
2578  /* Must apply correct cost/width data to Limit node */
2579  plan->startup_cost = mminfo->path->startup_cost;
2580  plan->total_cost = mminfo->pathcost;
2581  plan->plan_rows = 1;
2582  plan->plan_width = mminfo->path->pathtarget->width;
2583  plan->parallel_aware = false;
2584  plan->parallel_safe = mminfo->path->parallel_safe;
2585 
2586  /* Convert the plan into an InitPlan in the outer query. */
2587  SS_make_initplan_from_plan(root, subroot, plan, mminfo->param);
2588  }
2589 
2590  /* Generate the output plan --- basically just a Result */
2591  tlist = build_path_tlist(root, &best_path->path);
2592 
2593  plan = make_result(tlist, (Node *) best_path->quals, NULL);
2594 
2595  copy_generic_path_info(&plan->plan, (Path *) best_path);
2596 
2597  /*
2598  * During setrefs.c, we'll need to replace references to the Agg nodes
2599  * with InitPlan output params. (We can't just do that locally in the
2600  * MinMaxAgg node, because path nodes above here may have Agg references
2601  * as well.) Save the mmaggregates list to tell setrefs.c to do that.
2602  */
2603  Assert(root->minmax_aggs == NIL);
2604  root->minmax_aggs = best_path->mmaggregates;
2605 
2606  return plan;
2607 }
2608 
2609 /*
2610  * create_windowagg_plan
2611  *
2612  * Create a WindowAgg plan for 'best_path' and (recursively) plans
2613  * for its subpaths.
2614  */
2615 static WindowAgg *
2617 {
2618  WindowAgg *plan;
2619  WindowClause *wc = best_path->winclause;
2620  int numPart = list_length(wc->partitionClause);
2621  int numOrder = list_length(wc->orderClause);
2622  Plan *subplan;
2623  List *tlist;
2624  int partNumCols;
2625  AttrNumber *partColIdx;
2626  Oid *partOperators;
2627  Oid *partCollations;
2628  int ordNumCols;
2629  AttrNumber *ordColIdx;
2630  Oid *ordOperators;
2631  Oid *ordCollations;
2632  ListCell *lc;
2633 
2634  /*
2635  * Choice of tlist here is motivated by the fact that WindowAgg will be
2636  * storing the input rows of window frames in a tuplestore; it therefore
2637  * behooves us to request a small tlist to avoid wasting space. We do of
2638  * course need grouping columns to be available.
2639  */
2640  subplan = create_plan_recurse(root, best_path->subpath,
2642 
2643  tlist = build_path_tlist(root, &best_path->path);
2644 
2645  /*
2646  * Convert SortGroupClause lists into arrays of attr indexes and equality
2647  * operators, as wanted by executor.
2648  */
2649  partColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numPart);
2650  partOperators = (Oid *) palloc(sizeof(Oid) * numPart);
2651  partCollations = (Oid *) palloc(sizeof(Oid) * numPart);
2652 
2653  partNumCols = 0;
2654  foreach(lc, wc->partitionClause)
2655  {
2656  SortGroupClause *sgc = (SortGroupClause *) lfirst(lc);
2657  TargetEntry *tle = get_sortgroupclause_tle(sgc, subplan->targetlist);
2658 
2659  Assert(OidIsValid(sgc->eqop));
2660  partColIdx[partNumCols] = tle->resno;
2661  partOperators[partNumCols] = sgc->eqop;
2662  partCollations[partNumCols] = exprCollation((Node *) tle->expr);
2663  partNumCols++;
2664  }
2665 
2666  ordColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numOrder);
2667  ordOperators = (Oid *) palloc(sizeof(Oid) * numOrder);
2668  ordCollations = (Oid *) palloc(sizeof(Oid) * numOrder);
2669 
2670  ordNumCols = 0;
2671  foreach(lc, wc->orderClause)
2672  {
2673  SortGroupClause *sgc = (SortGroupClause *) lfirst(lc);
2674  TargetEntry *tle = get_sortgroupclause_tle(sgc, subplan->targetlist);
2675 
2676  Assert(OidIsValid(sgc->eqop));
2677  ordColIdx[ordNumCols] = tle->resno;
2678  ordOperators[ordNumCols] = sgc->eqop;
2679  ordCollations[ordNumCols] = exprCollation((Node *) tle->expr);
2680  ordNumCols++;
2681  }
2682 
2683  /* And finally we can make the WindowAgg node */
2684  plan = make_windowagg(tlist,
2685  wc->winref,
2686  partNumCols,
2687  partColIdx,
2688  partOperators,
2689  partCollations,
2690  ordNumCols,
2691  ordColIdx,
2692  ordOperators,
2693  ordCollations,
2694  wc->frameOptions,
2695  wc->startOffset,
2696  wc->endOffset,
2697  wc->startInRangeFunc,
2698  wc->endInRangeFunc,
2699  wc->inRangeColl,
2700  wc->inRangeAsc,
2701  wc->inRangeNullsFirst,
2702  best_path->runCondition,
2703  best_path->qual,
2704  best_path->topwindow,
2705  subplan);
2706 
2707  copy_generic_path_info(&plan->plan, (Path *) best_path);
2708 
2709  return plan;
2710 }
2711 
2712 /*
2713  * create_setop_plan
2714  *
2715  * Create a SetOp plan for 'best_path' and (recursively) plans
2716  * for its subpaths.
2717  */
2718 static SetOp *
2720 {
2721  SetOp *plan;
2722  Plan *subplan;
2723  long numGroups;
2724 
2725  /*
2726  * SetOp doesn't project, so tlist requirements pass through; moreover we
2727  * need grouping columns to be labeled.
2728  */
2729  subplan = create_plan_recurse(root, best_path->subpath,
2730  flags | CP_LABEL_TLIST);
2731 
2732  /* Convert numGroups to long int --- but 'ware overflow! */
2733  numGroups = clamp_cardinality_to_long(best_path->numGroups);
2734 
2735  plan = make_setop(best_path->cmd,
2736  best_path->strategy,
2737  subplan,
2738  best_path->distinctList,
2739  best_path->flagColIdx,
2740  best_path->firstFlag,
2741  numGroups);
2742 
2743  copy_generic_path_info(&plan->plan, (Path *) best_path);
2744 
2745  return plan;
2746 }
2747 
2748 /*
2749  * create_recursiveunion_plan
2750  *
2751  * Create a RecursiveUnion plan for 'best_path' and (recursively) plans
2752  * for its subpaths.
2753  */
2754 static RecursiveUnion *
2756 {
2758  Plan *leftplan;
2759  Plan *rightplan;
2760  List *tlist;
2761  long numGroups;
2762 
2763  /* Need both children to produce same tlist, so force it */
2764  leftplan = create_plan_recurse(root, best_path->leftpath, CP_EXACT_TLIST);
2765  rightplan = create_plan_recurse(root, best_path->rightpath, CP_EXACT_TLIST);
2766 
2767  tlist = build_path_tlist(root, &best_path->path);
2768 
2769  /* Convert numGroups to long int --- but 'ware overflow! */
2770  numGroups = clamp_cardinality_to_long(best_path->numGroups);
2771 
2772  plan = make_recursive_union(tlist,
2773  leftplan,
2774  rightplan,
2775  best_path->wtParam,
2776  best_path->distinctList,
2777  numGroups);
2778 
2779  copy_generic_path_info(&plan->plan, (Path *) best_path);
2780 
2781  return plan;
2782 }
2783 
2784 /*
2785  * create_lockrows_plan
2786  *
2787  * Create a LockRows plan for 'best_path' and (recursively) plans
2788  * for its subpaths.
2789  */
2790 static LockRows *
2792  int flags)
2793 {
2794  LockRows *plan;
2795  Plan *subplan;
2796 
2797  /* LockRows doesn't project, so tlist requirements pass through */
2798  subplan = create_plan_recurse(root, best_path->subpath, flags);
2799 
2800  plan = make_lockrows(subplan, best_path->rowMarks, best_path->epqParam);
2801 
2802  copy_generic_path_info(&plan->plan, (Path *) best_path);
2803 
2804  return plan;
2805 }
2806 
2807 /*
2808  * create_modifytable_plan
2809  * Create a ModifyTable plan for 'best_path'.
2810  *
2811  * Returns a Plan node.
2812  */
2813 static ModifyTable *
2815 {
2816  ModifyTable *plan;
2817  Path *subpath = best_path->subpath;
2818  Plan *subplan;
2819 
2820  /* Subplan must produce exactly the specified tlist */
2822 
2823  /* Transfer resname/resjunk labeling, too, to keep executor happy */
2824  apply_tlist_labeling(subplan->targetlist, root->processed_tlist);
2825 
2827  subplan,
2828  best_path->operation,
2829  best_path->canSetTag,
2830  best_path->nominalRelation,
2831  best_path->rootRelation,
2832  best_path->partColsUpdated,
2833  best_path->resultRelations,
2834  best_path->updateColnosLists,
2835  best_path->withCheckOptionLists,
2836  best_path->returningLists,
2837  best_path->rowMarks,
2838  best_path->onconflict,
2839  best_path->mergeActionLists,
2840  best_path->mergeJoinConditions,
2841  best_path->epqParam);
2842 
2843  copy_generic_path_info(&plan->plan, &best_path->path);
2844 
2845  return plan;
2846 }
2847 
2848 /*
2849  * create_limit_plan
2850  *
2851  * Create a Limit plan for 'best_path' and (recursively) plans
2852  * for its subpaths.
2853  */
2854 static Limit *
2856 {
2857  Limit *plan;
2858  Plan *subplan;
2859  int numUniqkeys = 0;
2860  AttrNumber *uniqColIdx = NULL;
2861  Oid *uniqOperators = NULL;
2862  Oid *uniqCollations = NULL;
2863 
2864  /* Limit doesn't project, so tlist requirements pass through */
2865  subplan = create_plan_recurse(root, best_path->subpath, flags);
2866 
2867  /* Extract information necessary for comparing rows for WITH TIES. */
2868  if (best_path->limitOption == LIMIT_OPTION_WITH_TIES)
2869  {
2870  Query *parse = root->parse;
2871  ListCell *l;
2872 
2873  numUniqkeys = list_length(parse->sortClause);
2874  uniqColIdx = (AttrNumber *) palloc(numUniqkeys * sizeof(AttrNumber));
2875  uniqOperators = (Oid *) palloc(numUniqkeys * sizeof(Oid));
2876  uniqCollations = (Oid *) palloc(numUniqkeys * sizeof(Oid));
2877 
2878  numUniqkeys = 0;
2879  foreach(l, parse->sortClause)
2880  {
2881  SortGroupClause *sortcl = (SortGroupClause *) lfirst(l);
2882  TargetEntry *tle = get_sortgroupclause_tle(sortcl, parse->targetList);
2883 
2884  uniqColIdx[numUniqkeys] = tle->resno;
2885  uniqOperators[numUniqkeys] = sortcl->eqop;
2886  uniqCollations[numUniqkeys] = exprCollation((Node *) tle->expr);
2887  numUniqkeys++;
2888  }
2889  }
2890 
2891  plan = make_limit(subplan,
2892  best_path->limitOffset,
2893  best_path->limitCount,
2894  best_path->limitOption,
2895  numUniqkeys, uniqColIdx, uniqOperators, uniqCollations);
2896 
2897  copy_generic_path_info(&plan->plan, (Path *) best_path);
2898 
2899  return plan;
2900 }
2901 
2902 
2903 /*****************************************************************************
2904  *
2905  * BASE-RELATION SCAN METHODS
2906  *
2907  *****************************************************************************/
2908 
2909 
2910 /*
2911  * create_seqscan_plan
2912  * Returns a seqscan plan for the base relation scanned by 'best_path'
2913  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2914  */
2915 static SeqScan *
2917  List *tlist, List *scan_clauses)
2918 {
2919  SeqScan *scan_plan;
2920  Index scan_relid = best_path->parent->relid;
2921 
2922  /* it should be a base rel... */
2923  Assert(scan_relid > 0);
2924  Assert(best_path->parent->rtekind == RTE_RELATION);
2925 
2926  /* Sort clauses into best execution order */
2927  scan_clauses = order_qual_clauses(root, scan_clauses);
2928 
2929  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
2930  scan_clauses = extract_actual_clauses(scan_clauses, false);
2931 
2932  /* Replace any outer-relation variables with nestloop params */
2933  if (best_path->param_info)
2934  {
2935  scan_clauses = (List *)
2936  replace_nestloop_params(root, (Node *) scan_clauses);
2937  }
2938 
2939  scan_plan = make_seqscan(tlist,
2940  scan_clauses,
2941  scan_relid);
2942 
2943  copy_generic_path_info(&scan_plan->scan.plan, best_path);
2944 
2945  return scan_plan;
2946 }
2947 
2948 /*
2949  * create_samplescan_plan
2950  * Returns a samplescan plan for the base relation scanned by 'best_path'
2951  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2952  */
2953 static SampleScan *
2955  List *tlist, List *scan_clauses)
2956 {
2957  SampleScan *scan_plan;
2958  Index scan_relid = best_path->parent->relid;
2959  RangeTblEntry *rte;
2960  TableSampleClause *tsc;
2961 
2962  /* it should be a base rel with a tablesample clause... */
2963  Assert(scan_relid > 0);
2964  rte = planner_rt_fetch(scan_relid, root);
2965  Assert(rte->rtekind == RTE_RELATION);
2966  tsc = rte->tablesample;
2967  Assert(tsc != NULL);
2968 
2969  /* Sort clauses into best execution order */
2970  scan_clauses = order_qual_clauses(root, scan_clauses);
2971 
2972  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
2973  scan_clauses = extract_actual_clauses(scan_clauses, false);
2974 
2975  /* Replace any outer-relation variables with nestloop params */
2976  if (best_path->param_info)
2977  {
2978  scan_clauses = (List *)
2979  replace_nestloop_params(root, (Node *) scan_clauses);
2980  tsc = (TableSampleClause *)
2981  replace_nestloop_params(root, (Node *) tsc);
2982  }
2983 
2984  scan_plan = make_samplescan(tlist,
2985  scan_clauses,
2986  scan_relid,
2987  tsc);
2988 
2989  copy_generic_path_info(&scan_plan->scan.plan, best_path);
2990 
2991  return scan_plan;
2992 }
2993 
2994 /*
2995  * create_indexscan_plan
2996  * Returns an indexscan plan for the base relation scanned by 'best_path'
2997  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2998  *
2999  * We use this for both plain IndexScans and IndexOnlyScans, because the
3000  * qual preprocessing work is the same for both. Note that the caller tells
3001  * us which to build --- we don't look at best_path->path.pathtype, because
3002  * create_bitmap_subplan needs to be able to override the prior decision.
3003  */
3004 static Scan *
3006  IndexPath *best_path,
3007  List *tlist,
3008  List *scan_clauses,
3009  bool indexonly)
3010 {
3011  Scan *scan_plan;
3012  List *indexclauses = best_path->indexclauses;
3013  List *indexorderbys = best_path->indexorderbys;
3014  Index baserelid = best_path->path.parent->relid;
3015  IndexOptInfo *indexinfo = best_path->indexinfo;
3016  Oid indexoid = indexinfo->indexoid;
3017  List *qpqual;
3018  List *stripped_indexquals;
3019  List *fixed_indexquals;
3020  List *fixed_indexorderbys;
3021  List *indexorderbyops = NIL;
3022  ListCell *l;
3023 
3024  /* it should be a base rel... */
3025  Assert(baserelid > 0);
3026  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3027  /* check the scan direction is valid */
3028  Assert(best_path->indexscandir == ForwardScanDirection ||
3029  best_path->indexscandir == BackwardScanDirection);
3030 
3031  /*
3032  * Extract the index qual expressions (stripped of RestrictInfos) from the
3033  * IndexClauses list, and prepare a copy with index Vars substituted for
3034  * table Vars. (This step also does replace_nestloop_params on the
3035  * fixed_indexquals.)
3036  */
3037  fix_indexqual_references(root, best_path,
3038  &stripped_indexquals,
3039  &fixed_indexquals);
3040 
3041  /*
3042  * Likewise fix up index attr references in the ORDER BY expressions.
3043  */
3044  fixed_indexorderbys = fix_indexorderby_references(root, best_path);
3045 
3046  /*
3047  * The qpqual list must contain all restrictions not automatically handled
3048  * by the index, other than pseudoconstant clauses which will be handled
3049  * by a separate gating plan node. All the predicates in the indexquals
3050  * will be checked (either by the index itself, or by nodeIndexscan.c),
3051  * but if there are any "special" operators involved then they must be
3052  * included in qpqual. The upshot is that qpqual must contain
3053  * scan_clauses minus whatever appears in indexquals.
3054  *
3055  * is_redundant_with_indexclauses() detects cases where a scan clause is
3056  * present in the indexclauses list or is generated from the same
3057  * EquivalenceClass as some indexclause, and is therefore redundant with
3058  * it, though not equal. (The latter happens when indxpath.c prefers a
3059  * different derived equality than what generate_join_implied_equalities
3060  * picked for a parameterized scan's ppi_clauses.) Note that it will not
3061  * match to lossy index clauses, which is critical because we have to
3062  * include the original clause in qpqual in that case.
3063  *
3064  * In some situations (particularly with OR'd index conditions) we may
3065  * have scan_clauses that are not equal to, but are logically implied by,
3066  * the index quals; so we also try a predicate_implied_by() check to see
3067  * if we can discard quals that way. (predicate_implied_by assumes its
3068  * first input contains only immutable functions, so we have to check
3069  * that.)
3070  *
3071  * Note: if you change this bit of code you should also look at
3072  * extract_nonindex_conditions() in costsize.c.
3073  */
3074  qpqual = NIL;
3075  foreach(l, scan_clauses)
3076  {
3077  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3078 
3079  if (rinfo->pseudoconstant)
3080  continue; /* we may drop pseudoconstants here */
3081  if (is_redundant_with_indexclauses(rinfo, indexclauses))
3082  continue; /* dup or derived from same EquivalenceClass */
3083  if (!contain_mutable_functions((Node *) rinfo->clause) &&
3084  predicate_implied_by(list_make1(rinfo->clause), stripped_indexquals,
3085  false))
3086  continue; /* provably implied by indexquals */
3087  qpqual = lappend(qpqual, rinfo);
3088  }
3089 
3090  /* Sort clauses into best execution order */
3091  qpqual = order_qual_clauses(root, qpqual);
3092 
3093  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3094  qpqual = extract_actual_clauses(qpqual, false);
3095 
3096  /*
3097  * We have to replace any outer-relation variables with nestloop params in
3098  * the indexqualorig, qpqual, and indexorderbyorig expressions. A bit
3099  * annoying to have to do this separately from the processing in
3100  * fix_indexqual_references --- rethink this when generalizing the inner
3101  * indexscan support. But note we can't really do this earlier because
3102  * it'd break the comparisons to predicates above ... (or would it? Those
3103  * wouldn't have outer refs)
3104  */
3105  if (best_path->path.param_info)
3106  {
3107  stripped_indexquals = (List *)
3108  replace_nestloop_params(root, (Node *) stripped_indexquals);
3109  qpqual = (List *)
3110  replace_nestloop_params(root, (Node *) qpqual);
3111  indexorderbys = (List *)
3112  replace_nestloop_params(root, (Node *) indexorderbys);
3113  }
3114 
3115  /*
3116  * If there are ORDER BY expressions, look up the sort operators for their
3117  * result datatypes.
3118  */
3119  if (indexorderbys)
3120  {
3121  ListCell *pathkeyCell,
3122  *exprCell;
3123 
3124  /*
3125  * PathKey contains OID of the btree opfamily we're sorting by, but
3126  * that's not quite enough because we need the expression's datatype
3127  * to look up the sort operator in the operator family.
3128  */
3129  Assert(list_length(best_path->path.pathkeys) == list_length(indexorderbys));
3130  forboth(pathkeyCell, best_path->path.pathkeys, exprCell, indexorderbys)
3131  {
3132  PathKey *pathkey = (PathKey *) lfirst(pathkeyCell);
3133  Node *expr = (Node *) lfirst(exprCell);
3134  Oid exprtype = exprType(expr);
3135  Oid sortop;
3136 
3137  /* Get sort operator from opfamily */
3138  sortop = get_opfamily_member(pathkey->pk_opfamily,
3139  exprtype,
3140  exprtype,
3141  pathkey->pk_strategy);
3142  if (!OidIsValid(sortop))
3143  elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3144  pathkey->pk_strategy, exprtype, exprtype, pathkey->pk_opfamily);
3145  indexorderbyops = lappend_oid(indexorderbyops, sortop);
3146  }
3147  }
3148 
3149  /*
3150  * For an index-only scan, we must mark indextlist entries as resjunk if
3151  * they are columns that the index AM can't return; this cues setrefs.c to
3152  * not generate references to those columns.
3153  */
3154  if (indexonly)
3155  {
3156  int i = 0;
3157 
3158  foreach(l, indexinfo->indextlist)
3159  {
3160  TargetEntry *indextle = (TargetEntry *) lfirst(l);
3161 
3162  indextle->resjunk = !indexinfo->canreturn[i];
3163  i++;
3164  }
3165  }
3166 
3167  /* Finally ready to build the plan node */
3168  if (indexonly)
3169  scan_plan = (Scan *) make_indexonlyscan(tlist,
3170  qpqual,
3171  baserelid,
3172  indexoid,
3173  fixed_indexquals,
3174  stripped_indexquals,
3175  fixed_indexorderbys,
3176  indexinfo->indextlist,
3177  best_path->indexscandir);
3178  else
3179  scan_plan = (Scan *) make_indexscan(tlist,
3180  qpqual,
3181  baserelid,
3182  indexoid,
3183  fixed_indexquals,
3184  stripped_indexquals,
3185  fixed_indexorderbys,
3186  indexorderbys,
3187  indexorderbyops,
3188  best_path->indexscandir);
3189 
3190  copy_generic_path_info(&scan_plan->plan, &best_path->path);
3191 
3192  return scan_plan;
3193 }
3194 
3195 /*
3196  * create_bitmap_scan_plan
3197  * Returns a bitmap scan plan for the base relation scanned by 'best_path'
3198  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3199  */
3200 static BitmapHeapScan *
3202  BitmapHeapPath *best_path,
3203  List *tlist,
3204  List *scan_clauses)
3205 {
3206  Index baserelid = best_path->path.parent->relid;
3207  Plan *bitmapqualplan;
3208  List *bitmapqualorig;
3209  List *indexquals;
3210  List *indexECs;
3211  List *qpqual;
3212  ListCell *l;
3213  BitmapHeapScan *scan_plan;
3214 
3215  /* it should be a base rel... */
3216  Assert(baserelid > 0);
3217  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3218 
3219  /* Process the bitmapqual tree into a Plan tree and qual lists */
3220  bitmapqualplan = create_bitmap_subplan(root, best_path->bitmapqual,
3221  &bitmapqualorig, &indexquals,
3222  &indexECs);
3223 
3224  if (best_path->path.parallel_aware)
3225  bitmap_subplan_mark_shared(bitmapqualplan);
3226 
3227  /*
3228  * The qpqual list must contain all restrictions not automatically handled
3229  * by the index, other than pseudoconstant clauses which will be handled
3230  * by a separate gating plan node. All the predicates in the indexquals
3231  * will be checked (either by the index itself, or by
3232  * nodeBitmapHeapscan.c), but if there are any "special" operators
3233  * involved then they must be added to qpqual. The upshot is that qpqual
3234  * must contain scan_clauses minus whatever appears in indexquals.
3235  *
3236  * This loop is similar to the comparable code in create_indexscan_plan(),
3237  * but with some differences because it has to compare the scan clauses to
3238  * stripped (no RestrictInfos) indexquals. See comments there for more
3239  * info.
3240  *
3241  * In normal cases simple equal() checks will be enough to spot duplicate
3242  * clauses, so we try that first. We next see if the scan clause is
3243  * redundant with any top-level indexqual by virtue of being generated
3244  * from the same EC. After that, try predicate_implied_by().
3245  *
3246  * Unlike create_indexscan_plan(), the predicate_implied_by() test here is
3247  * useful for getting rid of qpquals that are implied by index predicates,
3248  * because the predicate conditions are included in the "indexquals"
3249  * returned by create_bitmap_subplan(). Bitmap scans have to do it that
3250  * way because predicate conditions need to be rechecked if the scan
3251  * becomes lossy, so they have to be included in bitmapqualorig.
3252  */
3253  qpqual = NIL;
3254  foreach(l, scan_clauses)
3255  {
3256  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3257  Node *clause = (Node *) rinfo->clause;
3258 
3259  if (rinfo->pseudoconstant)
3260  continue; /* we may drop pseudoconstants here */
3261  if (list_member(indexquals, clause))
3262  continue; /* simple duplicate */
3263  if (rinfo->parent_ec && list_member_ptr(indexECs, rinfo->parent_ec))
3264  continue; /* derived from same EquivalenceClass */
3265  if (!contain_mutable_functions(clause) &&
3266  predicate_implied_by(list_make1(clause), indexquals, false))
3267  continue; /* provably implied by indexquals */
3268  qpqual = lappend(qpqual, rinfo);
3269  }
3270 
3271  /* Sort clauses into best execution order */
3272  qpqual = order_qual_clauses(root, qpqual);
3273 
3274  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3275  qpqual = extract_actual_clauses(qpqual, false);
3276 
3277  /*
3278  * When dealing with special operators, we will at this point have
3279  * duplicate clauses in qpqual and bitmapqualorig. We may as well drop
3280  * 'em from bitmapqualorig, since there's no point in making the tests
3281  * twice.
3282  */
3283  bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual);
3284 
3285  /*
3286  * We have to replace any outer-relation variables with nestloop params in
3287  * the qpqual and bitmapqualorig expressions. (This was already done for
3288  * expressions attached to plan nodes in the bitmapqualplan tree.)
3289  */
3290  if (best_path->path.param_info)
3291  {
3292  qpqual = (List *)
3293  replace_nestloop_params(root, (Node *) qpqual);
3294  bitmapqualorig = (List *)
3295  replace_nestloop_params(root, (Node *) bitmapqualorig);
3296  }
3297 
3298  /* Finally ready to build the plan node */
3299  scan_plan = make_bitmap_heapscan(tlist,
3300  qpqual,
3301  bitmapqualplan,
3302  bitmapqualorig,
3303  baserelid);
3304 
3305  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3306 
3307  return scan_plan;
3308 }
3309 
3310 /*
3311  * Given a bitmapqual tree, generate the Plan tree that implements it
3312  *
3313  * As byproducts, we also return in *qual and *indexqual the qual lists
3314  * (in implicit-AND form, without RestrictInfos) describing the original index
3315  * conditions and the generated indexqual conditions. (These are the same in
3316  * simple cases, but when special index operators are involved, the former
3317  * list includes the special conditions while the latter includes the actual
3318  * indexable conditions derived from them.) Both lists include partial-index
3319  * predicates, because we have to recheck predicates as well as index
3320  * conditions if the bitmap scan becomes lossy.
3321  *
3322  * In addition, we return a list of EquivalenceClass pointers for all the
3323  * top-level indexquals that were possibly-redundantly derived from ECs.
3324  * This allows removal of scan_clauses that are redundant with such quals.
3325  * (We do not attempt to detect such redundancies for quals that are within
3326  * OR subtrees. This could be done in a less hacky way if we returned the
3327  * indexquals in RestrictInfo form, but that would be slower and still pretty
3328  * messy, since we'd have to build new RestrictInfos in many cases.)
3329  */
3330 static Plan *
3332  List **qual, List **indexqual, List **indexECs)
3333 {
3334  Plan *plan;
3335 
3336  if (IsA(bitmapqual, BitmapAndPath))
3337  {
3338  BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
3339  List *subplans = NIL;
3340  List *subquals = NIL;
3341  List *subindexquals = NIL;
3342  List *subindexECs = NIL;
3343  ListCell *l;
3344 
3345  /*
3346  * There may well be redundant quals among the subplans, since a
3347  * top-level WHERE qual might have gotten used to form several
3348  * different index quals. We don't try exceedingly hard to eliminate
3349  * redundancies, but we do eliminate obvious duplicates by using
3350  * list_concat_unique.
3351  */
3352  foreach(l, apath->bitmapquals)
3353  {
3354  Plan *subplan;
3355  List *subqual;
3356  List *subindexqual;
3357  List *subindexEC;
3358 
3359  subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
3360  &subqual, &subindexqual,
3361  &subindexEC);
3362  subplans = lappend(subplans, subplan);
3363  subquals = list_concat_unique(subquals, subqual);
3364  subindexquals = list_concat_unique(subindexquals, subindexqual);
3365  /* Duplicates in indexECs aren't worth getting rid of */
3366  subindexECs = list_concat(subindexECs, subindexEC);
3367  }
3368  plan = (Plan *) make_bitmap_and(subplans);
3369  plan->startup_cost = apath->path.startup_cost;
3370  plan->total_cost = apath->path.total_cost;
3371  plan->plan_rows =
3372  clamp_row_est(apath->bitmapselectivity * apath->path.parent->tuples);
3373  plan->plan_width = 0; /* meaningless */
3374  plan->parallel_aware = false;
3375  plan->parallel_safe = apath->path.parallel_safe;
3376  *qual = subquals;
3377  *indexqual = subindexquals;
3378  *indexECs = subindexECs;
3379  }
3380  else if (IsA(bitmapqual, BitmapOrPath))
3381  {
3382  BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
3383  List *subplans = NIL;
3384  List *subquals = NIL;
3385  List *subindexquals = NIL;
3386  bool const_true_subqual = false;
3387  bool const_true_subindexqual = false;
3388  ListCell *l;
3389 
3390  /*
3391  * Here, we only detect qual-free subplans. A qual-free subplan would
3392  * cause us to generate "... OR true ..." which we may as well reduce
3393  * to just "true". We do not try to eliminate redundant subclauses
3394  * because (a) it's not as likely as in the AND case, and (b) we might
3395  * well be working with hundreds or even thousands of OR conditions,
3396  * perhaps from a long IN list. The performance of list_append_unique
3397  * would be unacceptable.
3398  */
3399  foreach(l, opath->bitmapquals)
3400  {
3401  Plan *subplan;
3402  List *subqual;
3403  List *subindexqual;
3404  List *subindexEC;
3405 
3406  subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
3407  &subqual, &subindexqual,
3408  &subindexEC);
3409  subplans = lappend(subplans, subplan);
3410  if (subqual == NIL)
3411  const_true_subqual = true;
3412  else if (!const_true_subqual)
3413  subquals = lappend(subquals,
3414  make_ands_explicit(subqual));
3415  if (subindexqual == NIL)
3416  const_true_subindexqual = true;
3417  else if (!const_true_subindexqual)
3418  subindexquals = lappend(subindexquals,
3419  make_ands_explicit(subindexqual));
3420  }
3421 
3422  /*
3423  * In the presence of ScalarArrayOpExpr quals, we might have built
3424  * BitmapOrPaths with just one subpath; don't add an OR step.
3425  */
3426  if (list_length(subplans) == 1)
3427  {
3428  plan = (Plan *) linitial(subplans);
3429  }
3430  else
3431  {
3432  plan = (Plan *) make_bitmap_or(subplans);
3433  plan->startup_cost = opath->path.startup_cost;
3434  plan->total_cost = opath->path.total_cost;
3435  plan->plan_rows =
3436  clamp_row_est(opath->bitmapselectivity * opath->path.parent->tuples);
3437  plan->plan_width = 0; /* meaningless */
3438  plan->parallel_aware = false;
3439  plan->parallel_safe = opath->path.parallel_safe;
3440  }
3441 
3442  /*
3443  * If there were constant-TRUE subquals, the OR reduces to constant
3444  * TRUE. Also, avoid generating one-element ORs, which could happen
3445  * due to redundancy elimination or ScalarArrayOpExpr quals.
3446  */
3447  if (const_true_subqual)
3448  *qual = NIL;
3449  else if (list_length(subquals) <= 1)
3450  *qual = subquals;
3451  else
3452  *qual = list_make1(make_orclause(subquals));
3453  if (const_true_subindexqual)
3454  *indexqual = NIL;
3455  else if (list_length(subindexquals) <= 1)
3456  *indexqual = subindexquals;
3457  else
3458  *indexqual = list_make1(make_orclause(subindexquals));
3459  *indexECs = NIL;
3460  }
3461  else if (IsA(bitmapqual, IndexPath))
3462  {
3463  IndexPath *ipath = (IndexPath *) bitmapqual;
3464  IndexScan *iscan;
3465  List *subquals;
3466  List *subindexquals;
3467  List *subindexECs;
3468  ListCell *l;
3469 
3470  /* Use the regular indexscan plan build machinery... */
3471  iscan = castNode(IndexScan,
3472  create_indexscan_plan(root, ipath,
3473  NIL, NIL, false));
3474  /* then convert to a bitmap indexscan */
3476  iscan->indexid,
3477  iscan->indexqual,
3478  iscan->indexqualorig);
3479  /* and set its cost/width fields appropriately */
3480  plan->startup_cost = 0.0;
3481  plan->total_cost = ipath->indextotalcost;
3482  plan->plan_rows =
3483  clamp_row_est(ipath->indexselectivity * ipath->path.parent->tuples);
3484  plan->plan_width = 0; /* meaningless */
3485  plan->parallel_aware = false;
3486  plan->parallel_safe = ipath->path.parallel_safe;
3487  /* Extract original index clauses, actual index quals, relevant ECs */
3488  subquals = NIL;
3489  subindexquals = NIL;
3490  subindexECs = NIL;
3491  foreach(l, ipath->indexclauses)
3492  {
3493  IndexClause *iclause = (IndexClause *) lfirst(l);
3494  RestrictInfo *rinfo = iclause->rinfo;
3495 
3496  Assert(!rinfo->pseudoconstant);
3497  subquals = lappend(subquals, rinfo->clause);
3498  subindexquals = list_concat(subindexquals,
3499  get_actual_clauses(iclause->indexquals));
3500  if (rinfo->parent_ec)
3501  subindexECs = lappend(subindexECs, rinfo->parent_ec);
3502  }
3503  /* We can add any index predicate conditions, too */
3504  foreach(l, ipath->indexinfo->indpred)
3505  {
3506  Expr *pred = (Expr *) lfirst(l);
3507 
3508  /*
3509  * We know that the index predicate must have been implied by the
3510  * query condition as a whole, but it may or may not be implied by
3511  * the conditions that got pushed into the bitmapqual. Avoid
3512  * generating redundant conditions.
3513  */
3514  if (!predicate_implied_by(list_make1(pred), subquals, false))
3515  {
3516  subquals = lappend(subquals, pred);
3517  subindexquals = lappend(subindexquals, pred);
3518  }
3519  }
3520  *qual = subquals;
3521  *indexqual = subindexquals;
3522  *indexECs = subindexECs;
3523  }
3524  else
3525  {
3526  elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
3527  plan = NULL; /* keep compiler quiet */
3528  }
3529 
3530  return plan;
3531 }
3532 
3533 /*
3534  * create_tidscan_plan
3535  * Returns a tidscan plan for the base relation scanned by 'best_path'
3536  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3537  */
3538 static TidScan *
3540  List *tlist, List *scan_clauses)
3541 {
3542  TidScan *scan_plan;
3543  Index scan_relid = best_path->path.parent->relid;
3544  List *tidquals = best_path->tidquals;
3545 
3546  /* it should be a base rel... */
3547  Assert(scan_relid > 0);
3548  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3549 
3550  /*
3551  * The qpqual list must contain all restrictions not enforced by the
3552  * tidquals list. Since tidquals has OR semantics, we have to be careful
3553  * about matching it up to scan_clauses. It's convenient to handle the
3554  * single-tidqual case separately from the multiple-tidqual case. In the
3555  * single-tidqual case, we look through the scan_clauses while they are
3556  * still in RestrictInfo form, and drop any that are redundant with the
3557  * tidqual.
3558  *
3559  * In normal cases simple pointer equality checks will be enough to spot
3560  * duplicate RestrictInfos, so we try that first.
3561  *
3562  * Another common case is that a scan_clauses entry is generated from the
3563  * same EquivalenceClass as some tidqual, and is therefore redundant with
3564  * it, though not equal.
3565  *
3566  * Unlike indexpaths, we don't bother with predicate_implied_by(); the
3567  * number of cases where it could win are pretty small.
3568  */
3569  if (list_length(tidquals) == 1)
3570  {
3571  List *qpqual = NIL;
3572  ListCell *l;
3573 
3574  foreach(l, scan_clauses)
3575  {
3576  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3577 
3578  if (rinfo->pseudoconstant)
3579  continue; /* we may drop pseudoconstants here */
3580  if (list_member_ptr(tidquals, rinfo))
3581  continue; /* simple duplicate */
3582  if (is_redundant_derived_clause(rinfo, tidquals))
3583  continue; /* derived from same EquivalenceClass */
3584  qpqual = lappend(qpqual, rinfo);
3585  }
3586  scan_clauses = qpqual;
3587  }
3588 
3589  /* Sort clauses into best execution order */
3590  scan_clauses = order_qual_clauses(root, scan_clauses);
3591 
3592  /* Reduce RestrictInfo lists to bare expressions; ignore pseudoconstants */
3593  tidquals = extract_actual_clauses(tidquals, false);
3594  scan_clauses = extract_actual_clauses(scan_clauses, false);
3595 
3596  /*
3597  * If we have multiple tidquals, it's more convenient to remove duplicate
3598  * scan_clauses after stripping the RestrictInfos. In this situation,
3599  * because the tidquals represent OR sub-clauses, they could not have come
3600  * from EquivalenceClasses so we don't have to worry about matching up
3601  * non-identical clauses. On the other hand, because tidpath.c will have
3602  * extracted those sub-clauses from some OR clause and built its own list,
3603  * we will certainly not have pointer equality to any scan clause. So
3604  * convert the tidquals list to an explicit OR clause and see if we can
3605  * match it via equal() to any scan clause.
3606  */
3607  if (list_length(tidquals) > 1)
3608  scan_clauses = list_difference(scan_clauses,
3609  list_make1(make_orclause(tidquals)));
3610 
3611  /* Replace any outer-relation variables with nestloop params */
3612  if (best_path->path.param_info)
3613  {
3614  tidquals = (List *)
3615  replace_nestloop_params(root, (Node *) tidquals);
3616  scan_clauses = (List *)
3617  replace_nestloop_params(root, (Node *) scan_clauses);
3618  }
3619 
3620  scan_plan = make_tidscan(tlist,
3621  scan_clauses,
3622  scan_relid,
3623  tidquals);
3624 
3625  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3626 
3627  return scan_plan;
3628 }
3629 
3630 /*
3631  * create_tidrangescan_plan
3632  * Returns a tidrangescan plan for the base relation scanned by 'best_path'
3633  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3634  */
3635 static TidRangeScan *
3637  List *tlist, List *scan_clauses)
3638 {
3639  TidRangeScan *scan_plan;
3640  Index scan_relid = best_path->path.parent->relid;
3641  List *tidrangequals = best_path->tidrangequals;
3642 
3643  /* it should be a base rel... */
3644  Assert(scan_relid > 0);
3645  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3646 
3647  /*
3648  * The qpqual list must contain all restrictions not enforced by the
3649  * tidrangequals list. tidrangequals has AND semantics, so we can simply
3650  * remove any qual that appears in it.
3651  */
3652  {
3653  List *qpqual = NIL;
3654  ListCell *l;
3655 
3656  foreach(l, scan_clauses)
3657  {
3658  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3659 
3660  if (rinfo->pseudoconstant)
3661  continue; /* we may drop pseudoconstants here */
3662  if (list_member_ptr(tidrangequals, rinfo))
3663  continue; /* simple duplicate */
3664  qpqual = lappend(qpqual, rinfo);
3665  }
3666  scan_clauses = qpqual;
3667  }
3668 
3669  /* Sort clauses into best execution order */
3670  scan_clauses = order_qual_clauses(root, scan_clauses);
3671 
3672  /* Reduce RestrictInfo lists to bare expressions; ignore pseudoconstants */
3673  tidrangequals = extract_actual_clauses(tidrangequals, false);
3674  scan_clauses = extract_actual_clauses(scan_clauses, false);
3675 
3676  /* Replace any outer-relation variables with nestloop params */
3677  if (best_path->path.param_info)
3678  {
3679  tidrangequals = (List *)
3680  replace_nestloop_params(root, (Node *) tidrangequals);
3681  scan_clauses = (List *)
3682  replace_nestloop_params(root, (Node *) scan_clauses);
3683  }
3684 
3685  scan_plan = make_tidrangescan(tlist,
3686  scan_clauses,
3687  scan_relid,
3688  tidrangequals);
3689 
3690  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3691 
3692  return scan_plan;
3693 }
3694 
3695 /*
3696  * create_subqueryscan_plan
3697  * Returns a subqueryscan plan for the base relation scanned by 'best_path'
3698  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3699  */
3700 static SubqueryScan *
3702  List *tlist, List *scan_clauses)
3703 {
3704  SubqueryScan *scan_plan;
3705  RelOptInfo *rel = best_path->path.parent;
3706  Index scan_relid = rel->relid;
3707  Plan *subplan;
3708 
3709  /* it should be a subquery base rel... */
3710  Assert(scan_relid > 0);
3711  Assert(rel->rtekind == RTE_SUBQUERY);
3712 
3713  /*
3714  * Recursively create Plan from Path for subquery. Since we are entering
3715  * a different planner context (subroot), recurse to create_plan not
3716  * create_plan_recurse.
3717  */
3718  subplan = create_plan(rel->subroot, best_path->subpath);
3719 
3720  /* Sort clauses into best execution order */
3721  scan_clauses = order_qual_clauses(root, scan_clauses);
3722 
3723  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3724  scan_clauses = extract_actual_clauses(scan_clauses, false);
3725 
3726  /*
3727  * Replace any outer-relation variables with nestloop params.
3728  *
3729  * We must provide nestloop params for both lateral references of the
3730  * subquery and outer vars in the scan_clauses. It's better to assign the
3731  * former first, because that code path requires specific param IDs, while
3732  * replace_nestloop_params can adapt to the IDs assigned by
3733  * process_subquery_nestloop_params. This avoids possibly duplicating
3734  * nestloop params when the same Var is needed for both reasons.
3735  */
3736  if (best_path->path.param_info)
3737  {
3739  rel->subplan_params);
3740  scan_clauses = (List *)
3741  replace_nestloop_params(root, (Node *) scan_clauses);
3742  }
3743 
3744  scan_plan = make_subqueryscan(tlist,
3745  scan_clauses,
3746  scan_relid,
3747  subplan);
3748 
3749  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3750 
3751  return scan_plan;
3752 }
3753 
3754 /*
3755  * create_functionscan_plan
3756  * Returns a functionscan plan for the base relation scanned by 'best_path'
3757  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3758  */
3759 static FunctionScan *
3761  List *tlist, List *scan_clauses)
3762 {
3763  FunctionScan *scan_plan;
3764  Index scan_relid = best_path->parent->relid;
3765  RangeTblEntry *rte;
3766  List *functions;
3767 
3768  /* it should be a function base rel... */
3769  Assert(scan_relid > 0);
3770  rte = planner_rt_fetch(scan_relid, root);
3771  Assert(rte->rtekind == RTE_FUNCTION);
3772  functions = rte->functions;
3773 
3774  /* Sort clauses into best execution order */
3775  scan_clauses = order_qual_clauses(root, scan_clauses);
3776 
3777  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3778  scan_clauses = extract_actual_clauses(scan_clauses, false);
3779 
3780  /* Replace any outer-relation variables with nestloop params */
3781  if (best_path->param_info)
3782  {
3783  scan_clauses = (List *)
3784  replace_nestloop_params(root, (Node *) scan_clauses);
3785  /* The function expressions could contain nestloop params, too */
3787  }
3788 
3789  scan_plan = make_functionscan(tlist, scan_clauses, scan_relid,
3790  functions, rte->funcordinality);
3791 
3792  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3793 
3794  return scan_plan;
3795 }
3796 
3797 /*
3798  * create_tablefuncscan_plan
3799  * Returns a tablefuncscan plan for the base relation scanned by 'best_path'
3800  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3801  */
3802 static TableFuncScan *
3804  List *tlist, List *scan_clauses)
3805 {
3806  TableFuncScan *scan_plan;
3807  Index scan_relid = best_path->parent->relid;
3808  RangeTblEntry *rte;
3809  TableFunc *tablefunc;
3810 
3811  /* it should be a function base rel... */
3812  Assert(scan_relid > 0);
3813  rte = planner_rt_fetch(scan_relid, root);
3814  Assert(rte->rtekind == RTE_TABLEFUNC);
3815  tablefunc = rte->tablefunc;
3816 
3817  /* Sort clauses into best execution order */
3818  scan_clauses = order_qual_clauses(root, scan_clauses);
3819 
3820  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3821  scan_clauses = extract_actual_clauses(scan_clauses, false);
3822 
3823  /* Replace any outer-relation variables with nestloop params */
3824  if (best_path->param_info)
3825  {
3826  scan_clauses = (List *)
3827  replace_nestloop_params(root, (Node *) scan_clauses);
3828  /* The function expressions could contain nestloop params, too */
3829  tablefunc = (TableFunc *) replace_nestloop_params(root, (Node *) tablefunc);
3830  }
3831 
3832  scan_plan = make_tablefuncscan(tlist, scan_clauses, scan_relid,
3833  tablefunc);
3834 
3835  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3836 
3837  return scan_plan;
3838 }
3839 
3840 /*
3841  * create_valuesscan_plan
3842  * Returns a valuesscan plan for the base relation scanned by 'best_path'
3843  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3844  */
3845 static ValuesScan *
3847  List *tlist, List *scan_clauses)
3848 {
3849  ValuesScan *scan_plan;
3850  Index scan_relid = best_path->parent->relid;
3851  RangeTblEntry *rte;
3852  List *values_lists;
3853 
3854  /* it should be a values base rel... */
3855  Assert(scan_relid > 0);
3856  rte = planner_rt_fetch(scan_relid, root);
3857  Assert(rte->rtekind == RTE_VALUES);
3858  values_lists = rte->values_lists;
3859 
3860  /* Sort clauses into best execution order */
3861  scan_clauses = order_qual_clauses(root, scan_clauses);
3862 
3863  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3864  scan_clauses = extract_actual_clauses(scan_clauses, false);
3865 
3866  /* Replace any outer-relation variables with nestloop params */
3867  if (best_path->param_info)
3868  {
3869  scan_clauses = (List *)
3870  replace_nestloop_params(root, (Node *) scan_clauses);
3871  /* The values lists could contain nestloop params, too */
3872  values_lists = (List *)
3873  replace_nestloop_params(root, (Node *) values_lists);
3874  }
3875 
3876  scan_plan = make_valuesscan(tlist, scan_clauses, scan_relid,
3877  values_lists);
3878 
3879  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3880 
3881  return scan_plan;
3882 }
3883 
3884 /*
3885  * create_ctescan_plan
3886  * Returns a ctescan plan for the base relation scanned by 'best_path'
3887  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3888  */
3889 static CteScan *
3891  List *tlist, List *scan_clauses)
3892 {
3893  CteScan *scan_plan;
3894  Index scan_relid = best_path->parent->relid;
3895  RangeTblEntry *rte;
3896  SubPlan *ctesplan = NULL;
3897  int plan_id;
3898  int cte_param_id;
3899  PlannerInfo *cteroot;
3900  Index levelsup;
3901  int ndx;
3902  ListCell *lc;
3903 
3904  Assert(scan_relid > 0);
3905  rte = planner_rt_fetch(scan_relid, root);
3906  Assert(rte->rtekind == RTE_CTE);
3907  Assert(!rte->self_reference);
3908 
3909  /*
3910  * Find the referenced CTE, and locate the SubPlan previously made for it.
3911  */
3912  levelsup = rte->ctelevelsup;
3913  cteroot = root;
3914  while (levelsup-- > 0)
3915  {
3916  cteroot = cteroot->parent_root;
3917  if (!cteroot) /* shouldn't happen */
3918  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3919  }
3920 
3921  /*
3922  * Note: cte_plan_ids can be shorter than cteList, if we are still working
3923  * on planning the CTEs (ie, this is a side-reference from another CTE).
3924  * So we mustn't use forboth here.
3925  */
3926  ndx = 0;
3927  foreach(lc, cteroot->parse->cteList)
3928  {
3929  CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
3930 
3931  if (strcmp(cte->ctename, rte->ctename) == 0)
3932  break;
3933  ndx++;
3934  }
3935  if (lc == NULL) /* shouldn't happen */
3936  elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
3937  if (ndx >= list_length(cteroot->cte_plan_ids))
3938  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
3939  plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
3940  if (plan_id <= 0)
3941  elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename);
3942  foreach(lc, cteroot->init_plans)
3943  {
3944  ctesplan = (SubPlan *) lfirst(lc);
3945  if (ctesplan->plan_id == plan_id)
3946  break;
3947  }
3948  if (lc == NULL) /* shouldn't happen */
3949  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
3950 
3951  /*
3952  * We need the CTE param ID, which is the sole member of the SubPlan's
3953  * setParam list.
3954  */
3955  cte_param_id = linitial_int(ctesplan->setParam);
3956 
3957  /* Sort clauses into best execution order */
3958  scan_clauses = order_qual_clauses(root, scan_clauses);
3959 
3960  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3961  scan_clauses = extract_actual_clauses(scan_clauses, false);
3962 
3963  /* Replace any outer-relation variables with nestloop params */
3964  if (best_path->param_info)
3965  {
3966  scan_clauses = (List *)
3967  replace_nestloop_params(root, (Node *) scan_clauses);
3968  }
3969 
3970  scan_plan = make_ctescan(tlist, scan_clauses, scan_relid,
3971  plan_id, cte_param_id);
3972 
3973  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3974 
3975  return scan_plan;
3976 }
3977 
3978 /*
3979  * create_namedtuplestorescan_plan
3980  * Returns a tuplestorescan plan for the base relation scanned by
3981  * 'best_path' with restriction clauses 'scan_clauses' and targetlist
3982  * 'tlist'.
3983  */
3984 static NamedTuplestoreScan *
3986  List *tlist, List *scan_clauses)
3987 {
3988  NamedTuplestoreScan *scan_plan;
3989  Index scan_relid = best_path->parent->relid;
3990  RangeTblEntry *rte;
3991 
3992  Assert(scan_relid > 0);
3993  rte = planner_rt_fetch(scan_relid, root);
3995 
3996  /* Sort clauses into best execution order */
3997  scan_clauses = order_qual_clauses(root, scan_clauses);
3998 
3999  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
4000  scan_clauses = extract_actual_clauses(scan_clauses, false);
4001 
4002  /* Replace any outer-relation variables with nestloop params */
4003  if (best_path->param_info)
4004  {
4005  scan_clauses = (List *)
4006  replace_nestloop_params(root, (Node *) scan_clauses);
4007  }
4008 
4009  scan_plan = make_namedtuplestorescan(tlist, scan_clauses, scan_relid,
4010  rte->enrname);
4011 
4012  copy_generic_path_info(&scan_plan->scan.plan, best_path);
4013 
4014  return scan_plan;
4015 }
4016 
4017 /*
4018  * create_resultscan_plan
4019  * Returns a Result plan for the RTE_RESULT base relation scanned by
4020  * 'best_path' with restriction clauses 'scan_clauses' and targetlist
4021  * 'tlist'.
4022  */
4023 static Result *
4025  List *tlist, List *scan_clauses)
4026 {
4027  Result *scan_plan;
4028  Index scan_relid = best_path->parent->relid;
4030 
4031  Assert(scan_relid > 0);
4032  rte = planner_rt_fetch(scan_relid, root);
4033  Assert(rte->rtekind == RTE_RESULT);
4034 
4035  /* Sort clauses into best execution order */
4036  scan_clauses = order_qual_clauses(root, scan_clauses);
4037 
4038  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
4039  scan_clauses = extract_actual_clauses(scan_clauses, false);
4040 
4041  /* Replace any outer-relation variables with nestloop params */
4042  if (best_path->param_info)
4043  {
4044  scan_clauses = (List *)
4045  replace_nestloop_params(root, (Node *) scan_clauses);
4046  }
4047 
4048  scan_plan = make_result(tlist, (Node *) scan_clauses, NULL);
4049 
4050  copy_generic_path_info(&scan_plan->plan, best_path);
4051 
4052  return scan_plan;
4053 }
4054 
4055 /*
4056  * create_worktablescan_plan
4057  * Returns a worktablescan plan for the base relation scanned by 'best_path'
4058  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
4059  */
4060 static WorkTableScan *
4062  List *tlist, List *scan_clauses)
4063 {
4064  WorkTableScan *scan_plan;
4065  Index scan_relid = best_path->parent->relid;
4066  RangeTblEntry *rte;
4067  Index levelsup;
4068  PlannerInfo *cteroot;
4069 
4070  Assert(scan_relid > 0);
4071  rte = planner_rt_fetch(scan_relid, root);
4072  Assert(rte->rtekind == RTE_CTE);
4073  Assert(rte->self_reference);
4074 
4075  /*
4076  * We need to find the worktable param ID, which is in the plan level
4077  * that's processing the recursive UNION, which is one level *below* where
4078  * the CTE comes from.
4079  */
4080  levelsup = rte->ctelevelsup;
4081  if (levelsup == 0) /* shouldn't happen */
4082  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
4083  levelsup--;
4084  cteroot = root;
4085  while (levelsup-- > 0)
4086  {
4087  cteroot = cteroot->parent_root;
4088  if (!cteroot) /* shouldn't happen */
4089  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
4090  }
4091  if (cteroot->wt_param_id < 0) /* shouldn't happen */
4092  elog(ERROR, "could not find param ID for CTE \"%s\"", rte->ctename);
4093 
4094  /* Sort clauses into best execution order */
4095  scan_clauses = order_qual_clauses(root, scan_clauses);
4096 
4097  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
4098  scan_clauses = extract_actual_clauses(scan_clauses, false);
4099 
4100  /* Replace any outer-relation variables with nestloop params */
4101  if (best_path->param_info)
4102  {
4103  scan_clauses = (List *)
4104  replace_nestloop_params(root, (Node *) scan_clauses);
4105  }
4106 
4107  scan_plan = make_worktablescan(tlist, scan_clauses, scan_relid,
4108  cteroot->wt_param_id);
4109 
4110  copy_generic_path_info(&scan_plan->scan.plan, best_path);
4111 
4112  return scan_plan;
4113 }
4114 
4115 /*
4116  * create_foreignscan_plan
4117  * Returns a foreignscan plan for the relation scanned by 'best_path'
4118  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
4119  */
4120 static ForeignScan *
4122  List *tlist, List *scan_clauses)
4123 {
4124  ForeignScan *scan_plan;
4125  RelOptInfo *rel = best_path->path.parent;
4126  Index scan_relid = rel->relid;
4127  Oid rel_oid = InvalidOid;
4128  Plan *outer_plan = NULL;
4129 
4130  Assert(rel->fdwroutine != NULL);
4131 
4132  /* transform the child path if any */
4133  if (best_path->fdw_outerpath)
4134  outer_plan = create_plan_recurse(root, best_path->fdw_outerpath,
4135  CP_EXACT_TLIST);
4136 
4137  /*
4138  * If we're scanning a base relation, fetch its OID. (Irrelevant if
4139  * scanning a join relation.)
4140  */
4141  if (scan_relid > 0)
4142  {
4143  RangeTblEntry *rte;
4144 
4145  Assert(rel->rtekind == RTE_RELATION);
4146  rte = planner_rt_fetch(scan_relid, root);
4147  Assert(rte->rtekind == RTE_RELATION);
4148  rel_oid = rte->relid;
4149  }
4150 
4151  /*
4152  * Sort clauses into best execution order. We do this first since the FDW
4153  * might have more info than we do and wish to adjust the ordering.
4154  */
4155  scan_clauses = order_qual_clauses(root, scan_clauses);
4156 
4157  /*
4158  * Let the FDW perform its processing on the restriction clauses and
4159  * generate the plan node. Note that the FDW might remove restriction
4160  * clauses that it intends to execute remotely, or even add more (if it
4161  * has selected some join clauses for remote use but also wants them
4162  * rechecked locally).
4163  */
4164  scan_plan = rel->fdwroutine->GetForeignPlan(root, rel, rel_oid,
4165  best_path,
4166  tlist, scan_clauses,
4167  outer_plan);
4168 
4169  /* Copy cost data from Path to Plan; no need to make FDW do this */
4170  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
4171 
4172  /* Copy user OID to access as; likewise no need to make FDW do this */
4173  scan_plan->checkAsUser = rel->userid;
4174 
4175  /* Copy foreign server OID; likewise, no need to make FDW do this */
4176  scan_plan->fs_server = rel->serverid;
4177 
4178  /*
4179  * Likewise, copy the relids that are represented by this foreign scan. An
4180  * upper rel doesn't have relids set, but it covers all the relations
4181  * participating in the underlying scan/join, so use root->all_query_rels.
4182  */
4183  if (rel->reloptkind == RELOPT_UPPER_REL)
4184  scan_plan->fs_relids = root->all_query_rels;
4185  else
4186  scan_plan->fs_relids = best_path->path.parent->relids;
4187 
4188  /*
4189  * Join relid sets include relevant outer joins, but FDWs may need to know
4190  * which are the included base rels. That's a bit tedious to get without
4191  * access to the plan-time data structures, so compute it here.
4192  */
4193  scan_plan->fs_base_relids = bms_difference(scan_plan->fs_relids,
4194  root->outer_join_rels);
4195 
4196  /*
4197  * If this is a foreign join, and to make it valid to push down we had to
4198  * assume that the current user is the same as some user explicitly named
4199  * in the query, mark the finished plan as depending on the current user.
4200  */
4201  if (rel->useridiscurrent)
4202  root->glob->dependsOnRole = true;
4203 
4204  /*
4205  * Replace any outer-relation variables with nestloop params in the qual,
4206  * fdw_exprs and fdw_recheck_quals expressions. We do this last so that
4207  * the FDW doesn't have to be involved. (Note that parts of fdw_exprs or
4208  * fdw_recheck_quals could have come from join clauses, so doing this
4209  * beforehand on the scan_clauses wouldn't work.) We assume
4210  * fdw_scan_tlist contains no such variables.
4211  */
4212  if (best_path->path.param_info)
4213  {
4214  scan_plan->scan.plan.qual = (List *)
4215  replace_nestloop_params(root, (Node *) scan_plan->scan.plan.qual);
4216  scan_plan->fdw_exprs = (List *)
4217  replace_nestloop_params(root, (Node *) scan_plan->fdw_exprs);
4218  scan_plan->fdw_recheck_quals = (List *)
4220  (Node *) scan_plan->fdw_recheck_quals);
4221  }
4222 
4223  /*
4224  * If rel is a base relation, detect whether any system columns are
4225  * requested from the rel. (If rel is a join relation, rel->relid will be
4226  * 0, but there can be no Var with relid 0 in the rel's targetlist or the
4227  * restriction clauses, so we skip this in that case. Note that any such
4228  * columns in base relations that were joined are assumed to be contained
4229  * in fdw_scan_tlist.) This is a bit of a kluge and might go away
4230  * someday, so we intentionally leave it out of the API presented to FDWs.
4231  */
4232  scan_plan->fsSystemCol = false;
4233  if (scan_relid > 0)
4234  {
4235  Bitmapset *attrs_used = NULL;
4236  ListCell *lc;
4237  int i;
4238 
4239  /*
4240  * First, examine all the attributes needed for joins or final output.
4241  * Note: we must look at rel's targetlist, not the attr_needed data,
4242  * because attr_needed isn't computed for inheritance child rels.
4243  */
4244  pull_varattnos((Node *) rel->reltarget->exprs, scan_relid, &attrs_used);
4245 
4246  /* Add all the attributes used by restriction clauses. */
4247  foreach(lc, rel->baserestrictinfo)
4248  {
4249  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4250 
4251  pull_varattnos((Node *) rinfo->clause, scan_relid, &attrs_used);
4252  }
4253 
4254  /* Now, are any system columns requested from rel? */
4255  for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++)
4256  {
4258  {
4259  scan_plan->fsSystemCol = true;
4260  break;
4261  }
4262  }
4263 
4264  bms_free(attrs_used);
4265  }
4266 
4267  return scan_plan;
4268 }
4269 
4270 /*
4271  * create_customscan_plan
4272  *
4273  * Transform a CustomPath into a Plan.
4274  */
4275 static CustomScan *
4277  List *tlist, List *scan_clauses)
4278 {
4279  CustomScan *cplan;
4280  RelOptInfo *rel = best_path->path.parent;
4281  List *custom_plans = NIL;
4282  ListCell *lc;
4283 
4284  /* Recursively transform child paths. */
4285  foreach(lc, best_path->custom_paths)
4286  {
4288  CP_EXACT_TLIST);
4289 
4290  custom_plans = lappend(custom_plans, plan);
4291  }
4292 
4293  /*
4294  * Sort clauses into the best execution order, although custom-scan
4295  * provider can reorder them again.
4296  */
4297  scan_clauses = order_qual_clauses(root, scan_clauses);
4298 
4299  /*
4300  * Invoke custom plan provider to create the Plan node represented by the
4301  * CustomPath.
4302  */
4303  cplan = castNode(CustomScan,
4304  best_path->methods->PlanCustomPath(root,
4305  rel,
4306  best_path,
4307  tlist,
4308  scan_clauses,
4309  custom_plans));
4310 
4311  /*
4312  * Copy cost data from Path to Plan; no need to make custom-plan providers
4313  * do this
4314  */
4315  copy_generic_path_info(&cplan->scan.plan, &best_path->path);
4316 
4317  /* Likewise, copy the relids that are represented by this custom scan */
4318  cplan->custom_relids = best_path->path.parent->relids;
4319 
4320  /*
4321  * Replace any outer-relation variables with nestloop params in the qual
4322  * and custom_exprs expressions. We do this last so that the custom-plan
4323  * provider doesn't have to be involved. (Note that parts of custom_exprs
4324  * could have come from join clauses, so doing this beforehand on the
4325  * scan_clauses wouldn't work.) We assume custom_scan_tlist contains no
4326  * such variables.
4327  */
4328  if (best_path->path.param_info)
4329  {
4330  cplan->scan.plan.qual = (List *)
4331  replace_nestloop_params(root, (Node *) cplan->scan.plan.qual);
4332  cplan->custom_exprs = (List *)
4334  }
4335 
4336  return cplan;
4337 }
4338 
4339 
4340 /*****************************************************************************
4341  *
4342  * JOIN METHODS
4343  *
4344  *****************************************************************************/
4345 
4346 static NestLoop *
4348  NestPath *best_path)
4349 {
4350  NestLoop *join_plan;
4351  Plan *outer_plan;
4352  Plan *inner_plan;
4353  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4354  List *joinrestrictclauses = best_path->jpath.joinrestrictinfo;
4355  List *joinclauses;
4356  List *otherclauses;
4357  Relids outerrelids;
4358  List *nestParams;
4359  Relids saveOuterRels = root->curOuterRels;
4360 
4361  /*
4362  * If the inner path is parameterized by the topmost parent of the outer
4363  * rel rather than the outer rel itself, fix that. (Nothing happens here
4364  * if it is not so parameterized.)
4365  */
4366  best_path->jpath.innerjoinpath =
4368  best_path->jpath.innerjoinpath,
4369  best_path->jpath.outerjoinpath->parent);
4370 
4371  /*
4372  * Failure here probably means that reparameterize_path_by_child() is not
4373  * in sync with path_is_reparameterizable_by_child().
4374  */
4375  Assert(best_path->jpath.innerjoinpath != NULL);
4376 
4377  /* NestLoop can project, so no need to be picky about child tlists */
4378  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath, 0);
4379 
4380  /* For a nestloop, include outer relids in curOuterRels for inner side */
4381  root->curOuterRels = bms_union(root->curOuterRels,
4382  best_path->jpath.outerjoinpath->parent->relids);
4383 
4384  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath, 0);
4385 
4386  /* Restore curOuterRels */
4387  bms_free(root->curOuterRels);
4388  root->curOuterRels = saveOuterRels;
4389 
4390  /* Sort join qual clauses into best execution order */
4391  joinrestrictclauses = order_qual_clauses(root, joinrestrictclauses);
4392 
4393  /* Get the join qual clauses (in plain expression form) */
4394  /* Any pseudoconstant clauses are ignored here */
4395  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4396  {
4397  extract_actual_join_clauses(joinrestrictclauses,
4398  best_path->jpath.path.parent->relids,
4399  &joinclauses, &otherclauses);
4400  }
4401  else
4402  {
4403  /* We can treat all clauses alike for an inner join */
4404  joinclauses = extract_actual_clauses(joinrestrictclauses, false);
4405  otherclauses = NIL;
4406  }
4407 
4408  /* Replace any outer-relation variables with nestloop params */
4409  if (best_path->jpath.path.param_info)
4410  {
4411  joinclauses = (List *)
4412  replace_nestloop_params(root, (Node *) joinclauses);
4413  otherclauses = (List *)
4414  replace_nestloop_params(root, (Node *) otherclauses);
4415  }
4416 
4417  /*
4418  * Identify any nestloop parameters that should be supplied by this join
4419  * node, and remove them from root->curOuterParams.
4420  */
4421  outerrelids = best_path->jpath.outerjoinpath->parent->relids;
4422  nestParams = identify_current_nestloop_params(root, outerrelids);
4423 
4424  join_plan = make_nestloop(tlist,
4425  joinclauses,
4426  otherclauses,
4427  nestParams,
4428  outer_plan,
4429  inner_plan,
4430  best_path->jpath.jointype,
4431  best_path->jpath.inner_unique);
4432 
4433  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4434 
4435  return join_plan;
4436 }
4437 
4438 static MergeJoin *
4440  MergePath *best_path)
4441 {
4442  MergeJoin *join_plan;
4443  Plan *outer_plan;
4444  Plan *inner_plan;
4445  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4446  List *joinclauses;
4447  List *otherclauses;
4448  List *mergeclauses;
4449  List *outerpathkeys;
4450  List *innerpathkeys;
4451  int nClauses;
4452  Oid *mergefamilies;
4453  Oid *mergecollations;
4454  int *mergestrategies;
4455  bool *mergenullsfirst;
4456  PathKey *opathkey;
4457  EquivalenceClass *opeclass;
4458  int i;
4459  ListCell *lc;
4460  ListCell *lop;
4461  ListCell *lip;
4462  Path *outer_path = best_path->jpath.outerjoinpath;
4463  Path *inner_path = best_path->jpath.innerjoinpath;
4464 
4465  /*
4466  * MergeJoin can project, so we don't have to demand exact tlists from the
4467  * inputs. However, if we're intending to sort an input's result, it's
4468  * best to request a small tlist so we aren't sorting more data than
4469  * necessary.
4470  */
4471  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath,
4472  (best_path->outersortkeys != NIL) ? CP_SMALL_TLIST : 0);
4473 
4474  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath,
4475  (best_path->innersortkeys != NIL) ? CP_SMALL_TLIST : 0);
4476 
4477  /* Sort join qual clauses into best execution order */
4478  /* NB: do NOT reorder the mergeclauses */
4479  joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
4480 
4481  /* Get the join qual clauses (in plain expression form) */
4482  /* Any pseudoconstant clauses are ignored here */
4483  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4484  {
4485  extract_actual_join_clauses(joinclauses,
4486  best_path->jpath.path.parent->relids,
4487  &joinclauses, &otherclauses);
4488  }
4489  else
4490  {
4491  /* We can treat all clauses alike for an inner join */
4492  joinclauses = extract_actual_clauses(joinclauses, false);
4493  otherclauses = NIL;
4494  }
4495 
4496  /*
4497  * Remove the mergeclauses from the list of join qual clauses, leaving the
4498  * list of quals that must be checked as qpquals.
4499  */
4500  mergeclauses = get_actual_clauses(best_path->path_mergeclauses);
4501  joinclauses = list_difference(joinclauses, mergeclauses);
4502 
4503  /*
4504  * Replace any outer-relation variables with nestloop params. There
4505  * should not be any in the mergeclauses.
4506  */
4507  if (best_path->jpath.path.param_info)
4508  {
4509  joinclauses = (List *)
4510  replace_nestloop_params(root, (Node *) joinclauses);
4511  otherclauses = (List *)
4512  replace_nestloop_params(root, (Node *) otherclauses);
4513  }
4514 
4515  /*
4516  * Rearrange mergeclauses, if needed, so that the outer variable is always
4517  * on the left; mark the mergeclause restrictinfos with correct
4518  * outer_is_left status.
4519  */
4520  mergeclauses = get_switched_clauses(best_path->path_mergeclauses,
4521  best_path->jpath.outerjoinpath->parent->relids);
4522 
4523  /*
4524  * Create explicit sort nodes for the outer and inner paths if necessary.
4525  */
4526  if (best_path->outersortkeys)
4527  {
4528  Relids outer_relids = outer_path->parent->relids;
4529  Sort *sort = make_sort_from_pathkeys(outer_plan,
4530  best_path->outersortkeys,
4531  outer_relids);
4532 
4534  outer_plan = (Plan *) sort;
4535  outerpathkeys = best_path->outersortkeys;
4536  }
4537  else
4538  outerpathkeys = best_path->jpath.outerjoinpath->pathkeys;
4539 
4540  if (best_path->innersortkeys)
4541  {
4542  Relids inner_relids = inner_path->parent->relids;
4543  Sort *sort = make_sort_from_pathkeys(inner_plan,
4544  best_path->innersortkeys,
4545  inner_relids);
4546 
4548  inner_plan = (Plan *) sort;
4549  innerpathkeys = best_path->innersortkeys;
4550  }
4551  else
4552  innerpathkeys = best_path->jpath.innerjoinpath->pathkeys;
4553 
4554  /*
4555  * If specified, add a materialize node to shield the inner plan from the
4556  * need to handle mark/restore.
4557  */
4558  if (best_path->materialize_inner)
4559  {
4560  Plan *matplan = (Plan *) make_material(inner_plan);
4561 
4562  /*
4563  * We assume the materialize will not spill to disk, and therefore
4564  * charge just cpu_operator_cost per tuple. (Keep this estimate in
4565  * sync with final_cost_mergejoin.)
4566  */
4567  copy_plan_costsize(matplan, inner_plan);
4568  matplan->total_cost += cpu_operator_cost * matplan->plan_rows;
4569 
4570  inner_plan = matplan;
4571  }
4572 
4573  /*
4574  * Compute the opfamily/collation/strategy/nullsfirst arrays needed by the
4575  * executor. The information is in the pathkeys for the two inputs, but
4576  * we need to be careful about the possibility of mergeclauses sharing a
4577  * pathkey, as well as the possibility that the inner pathkeys are not in
4578  * an order matching the mergeclauses.
4579  */
4580  nClauses = list_length(mergeclauses);
4581  Assert(nClauses == list_length(best_path->path_mergeclauses));
4582  mergefamilies = (Oid *) palloc(nClauses * sizeof(Oid));
4583  mergecollations = (Oid *) palloc(nClauses * sizeof(Oid));
4584  mergestrategies = (int *) palloc(nClauses * sizeof(int));
4585  mergenullsfirst = (bool *) palloc(nClauses * sizeof(bool));
4586 
4587  opathkey = NULL;
4588  opeclass = NULL;
4589  lop = list_head(outerpathkeys);
4590  lip = list_head(innerpathkeys);
4591  i = 0;
4592  foreach(lc, best_path->path_mergeclauses)
4593  {
4594  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
4595  EquivalenceClass *oeclass;
4596  EquivalenceClass *ieclass;
4597  PathKey *ipathkey = NULL;
4598  EquivalenceClass *ipeclass = NULL;
4599  bool first_inner_match = false;
4600 
4601  /* fetch outer/inner eclass from mergeclause */
4602  if (rinfo->outer_is_left)
4603  {
4604  oeclass = rinfo->left_ec;
4605  ieclass = rinfo->right_ec;
4606  }
4607  else
4608  {
4609  oeclass = rinfo->right_ec;
4610  ieclass = rinfo->left_ec;
4611  }
4612  Assert(oeclass != NULL);
4613  Assert(ieclass != NULL);
4614 
4615  /*
4616  * We must identify the pathkey elements associated with this clause
4617  * by matching the eclasses (which should give a unique match, since
4618  * the pathkey lists should be canonical). In typical cases the merge
4619  * clauses are one-to-one with the pathkeys, but when dealing with
4620  * partially redundant query conditions, things are more complicated.
4621  *
4622  * lop and lip reference the first as-yet-unmatched pathkey elements.
4623  * If they're NULL then all pathkey elements have been matched.
4624  *
4625  * The ordering of the outer pathkeys should match the mergeclauses,
4626  * by construction (see find_mergeclauses_for_outer_pathkeys()). There
4627  * could be more than one mergeclause for the same outer pathkey, but
4628  * no pathkey may be entirely skipped over.
4629  */
4630  if (oeclass != opeclass) /* multiple matches are not interesting */
4631  {
4632  /* doesn't match the current opathkey, so must match the next */
4633  if (lop == NULL)
4634  elog(ERROR, "outer pathkeys do not match mergeclauses");
4635  opathkey = (PathKey *) lfirst(lop);
4636  opeclass = opathkey->pk_eclass;
4637  lop = lnext(outerpathkeys, lop);
4638  if (oeclass != opeclass)
4639  elog(ERROR, "outer pathkeys do not match mergeclauses");
4640  }
4641 
4642  /*
4643  * The inner pathkeys likewise should not have skipped-over keys, but
4644  * it's possible for a mergeclause to reference some earlier inner
4645  * pathkey if we had redundant pathkeys. For example we might have
4646  * mergeclauses like "o.a = i.x AND o.b = i.y AND o.c = i.x". The
4647  * implied inner ordering is then "ORDER BY x, y, x", but the pathkey
4648  * mechanism drops the second sort by x as redundant, and this code
4649  * must cope.
4650  *
4651  * It's also possible for the implied inner-rel ordering to be like
4652  * "ORDER BY x, y, x DESC". We still drop the second instance of x as
4653  * redundant; but this means that the sort ordering of a redundant
4654  * inner pathkey should not be considered significant. So we must
4655  * detect whether this is the first clause matching an inner pathkey.
4656  */
4657  if (lip)
4658  {
4659  ipathkey = (PathKey *) lfirst(lip);
4660  ipeclass = ipathkey->pk_eclass;
4661  if (ieclass == ipeclass)
4662  {
4663  /* successful first match to this inner pathkey */
4664  lip = lnext(innerpathkeys, lip);
4665  first_inner_match = true;
4666  }
4667  }
4668  if (!first_inner_match)
4669  {
4670  /* redundant clause ... must match something before lip */
4671  ListCell *l2;
4672 
4673  foreach(l2, innerpathkeys)
4674  {
4675  if (l2 == lip)
4676  break;
4677  ipathkey = (PathKey *) lfirst(l2);
4678  ipeclass = ipathkey->pk_eclass;
4679  if (ieclass == ipeclass)
4680  break;
4681  }
4682  if (ieclass != ipeclass)
4683  elog(ERROR, "inner pathkeys do not match mergeclauses");
4684  }
4685 
4686  /*
4687  * The pathkeys should always match each other as to opfamily and
4688  * collation (which affect equality), but if we're considering a
4689  * redundant inner pathkey, its sort ordering might not match. In
4690  * such cases we may ignore the inner pathkey's sort ordering and use
4691  * the outer's. (In effect, we're lying to the executor about the
4692  * sort direction of this inner column, but it does not matter since
4693  * the run-time row comparisons would only reach this column when
4694  * there's equality for the earlier column containing the same eclass.
4695  * There could be only one value in this column for the range of inner
4696  * rows having a given value in the earlier column, so it does not
4697  * matter which way we imagine this column to be ordered.) But a
4698  * non-redundant inner pathkey had better match outer's ordering too.
4699  */
4700  if (opathkey->pk_opfamily != ipathkey->pk_opfamily ||
4701  opathkey->pk_eclass->ec_collation != ipathkey->pk_eclass->ec_collation)
4702  elog(ERROR, "left and right pathkeys do not match in mergejoin");
4703  if (first_inner_match &&
4704  (opathkey->pk_strategy != ipathkey->pk_strategy ||
4705  opathkey->pk_nulls_first != ipathkey->pk_nulls_first))
4706  elog(ERROR, "left and right pathkeys do not match in mergejoin");
4707 
4708  /* OK, save info for executor */
4709  mergefamilies[i] = opathkey->pk_opfamily;
4710  mergecollations[i] = opathkey->pk_eclass->ec_collation;
4711  mergestrategies[i] = opathkey->pk_strategy;
4712  mergenullsfirst[i] = opathkey->pk_nulls_first;
4713  i++;
4714  }
4715 
4716  /*
4717  * Note: it is not an error if we have additional pathkey elements (i.e.,
4718  * lop or lip isn't NULL here). The input paths might be better-sorted
4719  * than we need for the current mergejoin.
4720  */
4721 
4722  /*
4723  * Now we can build the mergejoin node.
4724  */
4725  join_plan = make_mergejoin(tlist,
4726  joinclauses,
4727  otherclauses,
4728  mergeclauses,
4729  mergefamilies,
4730  mergecollations,
4731  mergestrategies,
4732  mergenullsfirst,
4733  outer_plan,
4734  inner_plan,
4735  best_path->jpath.jointype,
4736  best_path->jpath.inner_unique,
4737  best_path->skip_mark_restore);
4738 
4739  /* Costs of sort and material steps are included in path cost already */
4740  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4741 
4742  return join_plan;
4743 }
4744 
4745 static HashJoin *
4747  HashPath *best_path)
4748 {
4749  HashJoin *join_plan;
4750  Hash *hash_plan;
4751  Plan *outer_plan;
4752  Plan *inner_plan;
4753  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4754  List *joinclauses;
4755  List *otherclauses;
4756  List *hashclauses;
4757  List *hashoperators = NIL;
4758  List *hashcollations = NIL;
4759  List *inner_hashkeys = NIL;
4760  List *outer_hashkeys = NIL;
4761  Oid skewTable = InvalidOid;
4762  AttrNumber skewColumn = InvalidAttrNumber;
4763  bool skewInherit = false;
4764  ListCell *lc;
4765 
4766  /*
4767  * HashJoin can project, so we don't have to demand exact tlists from the
4768  * inputs. However, it's best to request a small tlist from the inner
4769  * side, so that we aren't storing more data than necessary. Likewise, if
4770  * we anticipate batching, request a small tlist from the outer side so
4771  * that we don't put extra data in the outer batch files.
4772  */
4773  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath,
4774  (best_path->num_batches > 1) ? CP_SMALL_TLIST : 0);
4775 
4776  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath,
4777  CP_SMALL_TLIST);
4778 
4779  /* Sort join qual clauses into best execution order */
4780  joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
4781  /* There's no point in sorting the hash clauses ... */
4782 
4783  /* Get the join qual clauses (in plain expression form) */
4784  /* Any pseudoconstant clauses are ignored here */
4785  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4786  {
4787  extract_actual_join_clauses(joinclauses,
4788  best_path->jpath.path.parent->relids,
4789  &joinclauses, &otherclauses);
4790  }
4791  else
4792  {
4793  /* We can treat all clauses alike for an inner join */
4794  joinclauses = extract_actual_clauses(joinclauses, false);
4795  otherclauses = NIL;
4796  }
4797 
4798  /*
4799  * Remove the hashclauses from the list of join qual clauses, leaving the
4800  * list of quals that must be checked as qpquals.
4801  */
4802  hashclauses = get_actual_clauses(best_path->path_hashclauses);
4803  joinclauses = list_difference(joinclauses, hashclauses);
4804 
4805  /*
4806  * Replace any outer-relation variables with nestloop params. There
4807  * should not be any in the hashclauses.
4808  */
4809  if (best_path->jpath.path.param_info)
4810  {
4811  joinclauses = (List *)
4812  replace_nestloop_params(root, (Node *) joinclauses);
4813  otherclauses = (List *)
4814  replace_nestloop_params(root, (Node *) otherclauses);
4815  }
4816 
4817  /*
4818  * Rearrange hashclauses, if needed, so that the outer variable is always
4819  * on the left.
4820  */
4821  hashclauses = get_switched_clauses(best_path->path_hashclauses,
4822  best_path->jpath.outerjoinpath->parent->relids);
4823 
4824  /*
4825  * If there is a single join clause and we can identify the outer variable
4826  * as a simple column reference, supply its identity for possible use in
4827  * skew optimization. (Note: in principle we could do skew optimization
4828  * with multiple join clauses, but we'd have to be able to determine the
4829  * most common combinations of outer values, which we don't currently have
4830  * enough stats for.)
4831  */
4832  if (list_length(hashclauses) == 1)
4833  {
4834  OpExpr *clause = (OpExpr *) linitial(hashclauses);
4835  Node *node;
4836 
4837  Assert(is_opclause(clause));
4838  node = (Node *) linitial(clause->args);
4839  if (IsA(node, RelabelType))
4840  node = (Node *) ((RelabelType *) node)->arg;
4841  if (IsA(node, Var))
4842  {
4843  Var *var = (Var *) node;
4844  RangeTblEntry *rte;
4845 
4846  rte = root->simple_rte_array[var->varno];
4847  if (rte->rtekind == RTE_RELATION)
4848  {
4849  skewTable = rte->relid;
4850  skewColumn = var->varattno;
4851  skewInherit = rte->inh;
4852  }
4853  }
4854  }
4855 
4856  /*
4857  * Collect hash related information. The hashed expressions are
4858  * deconstructed into outer/inner expressions, so they can be computed
4859  * separately (inner expressions are used to build the hashtable via Hash,
4860  * outer expressions to perform lookups of tuples from HashJoin's outer
4861  * plan in the hashtable). Also collect operator information necessary to
4862  * build the hashtable.
4863  */
4864  foreach(lc, hashclauses)
4865  {
4866  OpExpr *hclause = lfirst_node(OpExpr, lc);
4867 
4868  hashoperators = lappend_oid(hashoperators, hclause->opno);
4869  hashcollations = lappend_oid(hashcollations, hclause->inputcollid);
4870  outer_hashkeys = lappend(outer_hashkeys, linitial(hclause->args));
4871  inner_hashkeys = lappend(inner_hashkeys, lsecond(hclause->args));
4872  }
4873 
4874  /*
4875  * Build the hash node and hash join node.
4876  */
4877  hash_plan = make_hash(inner_plan,
4878  inner_hashkeys,
4879  skewTable,
4880  skewColumn,
4881  skewInherit);
4882 
4883  /*
4884  * Set Hash node's startup & total costs equal to total cost of input
4885  * plan; this only affects EXPLAIN display not decisions.
4886  */
4887  copy_plan_costsize(&hash_plan->plan, inner_plan);
4888  hash_plan->plan.startup_cost = hash_plan->plan.total_cost;
4889 
4890  /*
4891  * If parallel-aware, the executor will also need an estimate of the total
4892  * number of rows expected from all participants so that it can size the
4893  * shared hash table.
4894  */
4895  if (best_path->jpath.path.parallel_aware)
4896  {
4897  hash_plan->plan.parallel_aware = true;
4898  hash_plan->rows_total = best_path->inner_rows_total;
4899  }
4900 
4901  join_plan = make_hashjoin(tlist,
4902  joinclauses,
4903  otherclauses,
4904  hashclauses,
4905  hashoperators,
4906  hashcollations,
4907  outer_hashkeys,
4908  outer_plan,
4909  (Plan *) hash_plan,
4910  best_path->jpath.jointype,
4911  best_path->jpath.inner_unique);
4912 
4913  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4914 
4915  return join_plan;
4916 }
4917 
4918 
4919 /*****************************************************************************
4920  *
4921  * SUPPORTING ROUTINES
4922  *
4923  *****************************************************************************/
4924 
4925 /*
4926  * replace_nestloop_params
4927  * Replace outer-relation Vars and PlaceHolderVars in the given expression
4928  * with nestloop Params
4929  *
4930  * All Vars and PlaceHolderVars belonging to the relation(s) identified by
4931  * root->curOuterRels are replaced by Params, and entries are added to
4932  * root->curOuterParams if not already present.
4933  */
4934 static Node *
4936 {
4937  /* No setup needed for tree walk, so away we go */
4938  return replace_nestloop_params_mutator(expr, root);
4939 }
4940 
4941 static Node *
4943 {
4944  if (node == NULL)
4945  return NULL;
4946  if (IsA(node, Var))
4947  {
4948  Var *var = (Var *) node;
4949 
4950  /* Upper-level Vars should be long gone at this point */
4951  Assert(var->varlevelsup == 0);
4952  /* If not to be replaced, we can just return the Var unmodified */
4953  if (IS_SPECIAL_VARNO(var->varno) ||
4954  !bms_is_member(var->varno, root->curOuterRels))
4955  return node;
4956  /* Replace the Var with a nestloop Param */
4957  return (Node *) replace_nestloop_param_var(root, var);
4958  }
4959  if (IsA(node, PlaceHolderVar))
4960  {
4961  PlaceHolderVar *phv = (PlaceHolderVar *) node;
4962 
4963  /* Upper-level PlaceHolderVars should be long gone at this point */
4964  Assert(phv->phlevelsup == 0);
4965 
4966  /* Check whether we need to replace the PHV */
4967  if (!bms_is_subset(find_placeholder_info(root, phv)->ph_eval_at,
4968  root->curOuterRels))
4969  {
4970  /*
4971  * We can't replace the whole PHV, but we might still need to
4972  * replace Vars or PHVs within its expression, in case it ends up
4973  * actually getting evaluated here. (It might get evaluated in
4974  * this plan node, or some child node; in the latter case we don't
4975  * really need to process the expression here, but we haven't got
4976  * enough info to tell if that's the case.) Flat-copy the PHV
4977  * node and then recurse on its expression.
4978  *
4979  * Note that after doing this, we might have different
4980  * representations of the contents of the same PHV in different
4981  * parts of the plan tree. This is OK because equal() will just
4982  * match on phid/phlevelsup, so setrefs.c will still recognize an
4983  * upper-level reference to a lower-level copy of the same PHV.
4984  */
4986 
4987  memcpy(newphv, phv, sizeof(PlaceHolderVar));
4988  newphv->phexpr = (Expr *)
4989  replace_nestloop_params_mutator((Node *) phv->phexpr,
4990  root);
4991  return (Node *) newphv;
4992  }
4993  /* Replace the PlaceHolderVar with a nestloop Param */
4995  }
4996  return expression_tree_mutator(node,
4998  (void *) root);
4999 }
5000 
5001 /*
5002  * fix_indexqual_references
5003  * Adjust indexqual clauses to the form the executor's indexqual
5004  * machinery needs.
5005  *
5006  * We have three tasks here:
5007  * * Select the actual qual clauses out of the input IndexClause list,
5008  * and remove RestrictInfo nodes from the qual clauses.
5009  * * Replace any outer-relation Var or PHV nodes with nestloop Params.
5010  * (XXX eventually, that responsibility should go elsewhere?)
5011  * * Index keys must be represented by Var nodes with varattno set to the
5012  * index's attribute number, not the attribute number in the original rel.
5013  *
5014  * *stripped_indexquals_p receives a list of the actual qual clauses.
5015  *
5016  * *fixed_indexquals_p receives a list of the adjusted quals. This is a copy
5017  * that shares no substructure with the original; this is needed in case there
5018  * are subplans in it (we need two separate copies of the subplan tree, or
5019  * things will go awry).
5020  */
5021 static void
5023  List **stripped_indexquals_p, List **fixed_indexquals_p)
5024 {
5025  IndexOptInfo *index = index_path->indexinfo;
5026  List *stripped_indexquals;
5027  List *fixed_indexquals;
5028  ListCell *lc;
5029 
5030  stripped_indexquals = fixed_indexquals = NIL;
5031 
5032  foreach(lc, index_path->indexclauses)
5033  {
5034  IndexClause *iclause = lfirst_node(IndexClause, lc);
5035  int indexcol = iclause->indexcol;
5036  ListCell *lc2;
5037 
5038  foreach(lc2, iclause->indexquals)
5039  {
5040  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc2);
5041  Node *clause = (Node *) rinfo->clause;
5042 
5043  stripped_indexquals = lappend(stripped_indexquals, clause);
5044  clause = fix_indexqual_clause(root, index, indexcol,
5045  clause, iclause->indexcols);
5046  fixed_indexquals = lappend(fixed_indexquals, clause);
5047  }
5048  }
5049 
5050  *stripped_indexquals_p = stripped_indexquals;
5051  *fixed_indexquals_p = fixed_indexquals;
5052 }
5053 
5054 /*
5055  * fix_indexorderby_references
5056  * Adjust indexorderby clauses to the form the executor's index
5057  * machinery needs.
5058  *
5059  * This is a simplified version of fix_indexqual_references. The input is
5060  * bare clauses and a separate indexcol list, instead of IndexClauses.
5061  */
5062 static List *
5064 {
5065  IndexOptInfo *index = index_path->indexinfo;
5066  List *fixed_indexorderbys;
5067  ListCell *lcc,
5068  *lci;
5069 
5070  fixed_indexorderbys = NIL;
5071 
5072  forboth(lcc, index_path->indexorderbys, lci, index_path->indexorderbycols)
5073  {
5074  Node *clause = (Node *) lfirst(lcc);
5075  int indexcol = lfirst_int(lci);
5076 
5077  clause = fix_indexqual_clause(root, index, indexcol, clause, NIL);
5078  fixed_indexorderbys = lappend(fixed_indexorderbys, clause);
5079  }
5080 
5081  return fixed_indexorderbys;
5082 }
5083 
5084 /*
5085  * fix_indexqual_clause
5086  * Convert a single indexqual clause to the form needed by the executor.
5087  *
5088  * We replace nestloop params here, and replace the index key variables
5089  * or expressions by index Var nodes.
5090  */
5091 static Node *
5093  Node *clause, List *indexcolnos)
5094 {
5095  /*
5096  * Replace any outer-relation variables with nestloop params.
5097  *
5098  * This also makes a copy of the clause, so it's safe to modify it
5099  * in-place below.
5100  */
5101  clause = replace_nestloop_params(root, clause);
5102 
5103  if (IsA(clause, OpExpr))
5104  {
5105  OpExpr *op = (OpExpr *) clause;
5106 
5107  /* Replace the indexkey expression with an index Var. */
5109  index,
5110  indexcol);
5111  }
5112  else if (IsA(clause, RowCompareExpr))
5113  {
5114  RowCompareExpr *rc = (RowCompareExpr *) clause;
5115  ListCell *lca,
5116  *lcai;
5117 
5118  /* Replace the indexkey expressions with index Vars. */
5119  Assert(list_length(rc->largs) == list_length(indexcolnos));
5120  forboth(lca, rc->largs, lcai, indexcolnos)
5121  {
5123  index,
5124  lfirst_int(lcai));
5125  }
5126  }
5127  else if (IsA(clause, ScalarArrayOpExpr))
5128  {
5129  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
5130 
5131  /* Replace the indexkey expression with an index Var. */
5133  index,
5134  indexcol);
5135  }
5136  else if (IsA(clause, NullTest))
5137  {
5138  NullTest *nt = (NullTest *) clause;
5139 
5140  /* Replace the indexkey expression with an index Var. */
5141  nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg,
5142  index,
5143  indexcol);
5144  }
5145  else
5146  elog(ERROR, "unsupported indexqual type: %d",
5147  (int) nodeTag(clause));
5148 
5149  return clause;
5150 }
5151 
5152 /*
5153  * fix_indexqual_operand
5154  * Convert an indexqual expression to a Var referencing the index column.
5155  *
5156  * We represent index keys by Var nodes having varno == INDEX_VAR and varattno
5157  * equal to the index's attribute number (index column position).
5158  *
5159  * Most of the code here is just for sanity cross-checking that the given
5160  * expression actually matches the index column it's claimed to.
5161  */
5162 static Node *
5164 {
5165  Var *result;
5166  int pos;
5167  ListCell *indexpr_item;
5168 
5169  /*
5170  * Remove any binary-compatible relabeling of the indexkey
5171  */
5172  if (IsA(node, RelabelType))
5173  node = (Node *) ((RelabelType *) node)->arg;
5174 
5175  Assert(indexcol >= 0 && indexcol < index->ncolumns);
5176 
5177  if (index->indexkeys[indexcol] != 0)
5178  {
5179  /* It's a simple index column */
5180  if (IsA(node, Var) &&
5181  ((Var *) node)->varno == index->rel->relid &&
5182  ((Var *) node)->varattno == index->indexkeys[indexcol])
5183  {
5184  result = (Var *) copyObject(node);
5185  result->varno = INDEX_VAR;
5186  result->varattno = indexcol + 1;
5187  return (Node *) result;
5188  }
5189  else
5190  elog(ERROR, "index key does not match expected index column");
5191  }
5192 
5193  /* It's an index expression, so find and cross-check the expression */
5194  indexpr_item = list_head(index->indexprs);
5195  for (pos = 0; pos < index->ncolumns; pos++)
5196  {
5197  if (index->indexkeys[pos] == 0)
5198  {
5199  if (indexpr_item == NULL)
5200  elog(ERROR, "too few entries in indexprs list");
5201  if (pos == indexcol)
5202  {
5203  Node *indexkey;
5204 
5205  indexkey = (Node *) lfirst(indexpr_item);
5206  if (indexkey && IsA(indexkey, RelabelType))
5207  indexkey = (Node *) ((RelabelType *) indexkey)->arg;
5208  if (equal(node, indexkey))
5209  {
5210  result = makeVar(INDEX_VAR, indexcol + 1,
5211  exprType(lfirst(indexpr_item)), -1,
5212  exprCollation(lfirst(indexpr_item)),
5213  0);
5214  return (Node *) result;
5215  }
5216  else
5217  elog(ERROR, "index key does not match expected index column");
5218  }
5219  indexpr_item = lnext(index->indexprs, indexpr_item);
5220  }
5221  }
5222 
5223  /* Oops... */
5224  elog(ERROR, "index key does not match expected index column");
5225  return NULL; /* keep compiler quiet */
5226 }
5227 
5228 /*
5229  * get_switched_clauses
5230  * Given a list of merge or hash joinclauses (as RestrictInfo nodes),
5231  * extract the bare clauses, and rearrange the elements within the
5232  * clauses, if needed, so the outer join variable is on the left and
5233  * the inner is on the right. The original clause data structure is not
5234  * touched; a modified list is returned. We do, however, set the transient
5235  * outer_is_left field in each RestrictInfo to show which side was which.
5236  */
5237 static List *
5238 get_switched_clauses(List *clauses, Relids outerrelids)
5239 {
5240  List *t_list = NIL;
5241  ListCell *l;
5242 
5243  foreach(l, clauses)
5244  {
5245  RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(l);
5246  OpExpr *clause = (OpExpr *) restrictinfo->clause;
5247 
5248  Assert(is_opclause(clause));
5249  if (bms_is_subset(restrictinfo->right_relids, outerrelids))
5250  {
5251  /*
5252  * Duplicate just enough of the structure to allow commuting the
5253  * clause without changing the original list. Could use
5254  * copyObject, but a complete deep copy is overkill.
5255  */
5256  OpExpr *temp = makeNode(OpExpr);
5257 
5258  temp->opno = clause->opno;
5259  temp->opfuncid = InvalidOid;
5260  temp->opresulttype = clause->opresulttype;
5261  temp->opretset = clause->opretset;
5262  temp->opcollid = clause->opcollid;
5263  temp->inputcollid = clause->inputcollid;
5264  temp->args = list_copy(clause->args);
5265  temp->location = clause->location;
5266  /* Commute it --- note this modifies the temp node in-place. */
5267  CommuteOpExpr(temp);
5268  t_list = lappend(t_list, temp);
5269  restrictinfo->outer_is_left = false;
5270  }
5271  else
5272  {
5273  Assert(bms_is_subset(restrictinfo->left_relids, outerrelids));
5274  t_list = lappend(t_list, clause);
5275  restrictinfo->outer_is_left = true;
5276  }
5277  }
5278  return t_list;
5279 }
5280 
5281 /*
5282  * order_qual_clauses
5283  * Given a list of qual clauses that will all be evaluated at the same
5284  * plan node, sort the list into the order we want to check the quals
5285  * in at runtime.
5286  *
5287  * When security barrier quals are used in the query, we may have quals with
5288  * different security levels in the list. Quals of lower security_level
5289  * must go before quals of higher security_level, except that we can grant
5290  * exceptions to move up quals that are leakproof. When security level
5291  * doesn't force the decision, we prefer to order clauses by estimated
5292  * execution cost, cheapest first.
5293  *
5294  * Ideally the order should be driven by a combination of execution cost and
5295  * selectivity, but it's not immediately clear how to account for both,
5296  * and given the uncertainty of the estimates the reliability of the decisions
5297  * would be doubtful anyway. So we just order by security level then
5298  * estimated per-tuple cost, being careful not to change the order when
5299  * (as is often the case) the estimates are identical.
5300  *
5301  * Although this will work on either bare clauses or RestrictInfos, it's
5302  * much faster to apply it to RestrictInfos, since it can re-use cost
5303  * information that is cached in RestrictInfos. XXX in the bare-clause
5304  * case, we are also not able to apply security considerations. That is
5305  * all right for the moment, because the bare-clause case doesn't occur
5306  * anywhere that barrier quals could be present, but it would be better to
5307  * get rid of it.
5308  *
5309  * Note: some callers pass lists that contain entries that will later be
5310  * removed; this is the easiest way to let this routine see RestrictInfos
5311  * instead of bare clauses. This is another reason why trying to consider
5312  * selectivity in the ordering would likely do the wrong thing.
5313  */
5314 static List *
5316 {
5317  typedef struct
5318  {
5319  Node *clause;
5320  Cost cost;
5321  Index security_level;
5322  } QualItem;
5323  int nitems = list_length(clauses);
5324  QualItem *items;
5325  ListCell *lc;
5326  int i;
5327  List *result;
5328 
5329  /* No need to work hard for 0 or 1 clause */
5330  if (nitems <= 1)
5331  return clauses;
5332 
5333  /*
5334  * Collect the items and costs into an array. This is to avoid repeated
5335  * cost_qual_eval work if the inputs aren't RestrictInfos.
5336  */
5337  items = (QualItem *) palloc(nitems * sizeof(QualItem));
5338  i = 0;
5339  foreach(lc, clauses)
5340  {
5341  Node *clause = (Node *) lfirst(lc);
5342  QualCost qcost;
5343 
5344  cost_qual_eval_node(&qcost, clause, root);
5345  items[i].clause = clause;
5346  items[i].cost = qcost.per_tuple;
5347  if (IsA(clause, RestrictInfo))
5348  {
5349  RestrictInfo *rinfo = (RestrictInfo *) clause;
5350 
5351  /*
5352  * If a clause is leakproof, it doesn't have to be constrained by
5353  * its nominal security level. If it's also reasonably cheap
5354  * (here defined as 10X cpu_operator_cost), pretend it has
5355  * security_level 0, which will allow it to go in front of
5356  * more-expensive quals of lower security levels. Of course, that
5357  * will also force it to go in front of cheaper quals of its own
5358  * security level, which is not so great, but we can alleviate
5359  * that risk by applying the cost limit cutoff.
5360  */
5361  if (rinfo->leakproof && items[i].cost < 10 * cpu_operator_cost)
5362  items[i].security_level = 0;
5363  else
5364  items[i].security_level = rinfo->security_level;
5365  }
5366  else
5367  items[i].security_level = 0;
5368  i++;
5369  }
5370 
5371  /*
5372  * Sort. We don't use qsort() because it's not guaranteed stable for
5373  * equal keys. The expected number of entries is small enough that a
5374  * simple insertion sort should be good enough.
5375  */
5376  for (i = 1; i < nitems; i++)
5377  {
5378  QualItem newitem = items[i];
5379  int j;
5380 
5381  /* insert newitem into the already-sorted subarray */
5382  for (j = i; j > 0; j--)
5383  {
5384  QualItem *olditem = &items[j - 1];
5385 
5386  if (newitem.security_level > olditem->security_level ||
5387  (newitem.security_level == olditem->security_level &&
5388  newitem.cost >= olditem->cost))
5389  break;
5390  items[j] = *olditem;
5391  }
5392  items[j] = newitem;
5393  }
5394 
5395  /* Convert back to a list */
5396  result = NIL;
5397  for (i = 0; i < nitems; i++)
5398  result = lappend(result, items[i].clause);
5399 
5400  return result;
5401 }
5402 
5403 /*
5404  * Copy cost and size info from a Path node to the Plan node created from it.
5405  * The executor usually won't use this info, but it's needed by EXPLAIN.
5406  * Also copy the parallel-related flags, which the executor *will* use.
5407  */
5408 static void
5410 {
5411  dest->startup_cost = src->startup_cost;
5412  dest->total_cost = src->total_cost;
5413  dest->plan_rows = src->rows;
5414  dest->plan_width = src->pathtarget->width;
5415  dest->parallel_aware = src->parallel_aware;
5416  dest->parallel_safe = src->parallel_safe;
5417 }
5418 
5419 /*
5420  * Copy cost and size info from a lower plan node to an inserted node.
5421  * (Most callers alter the info after copying it.)
5422  */
5423 static void
5425 {
5426  dest->startup_cost = src->startup_cost;
5427  dest->total_cost = src->total_cost;
5428  dest->plan_rows = src->plan_rows;
5429  dest->plan_width = src->plan_width;
5430  /* Assume the inserted node is not parallel-aware. */
5431  dest->parallel_aware = false;
5432  /* Assume the inserted node is parallel-safe, if child plan is. */
5433  dest->parallel_safe = src->parallel_safe;
5434 }
5435 
5436 /*
5437  * Some places in this file build Sort nodes that don't have a directly
5438  * corresponding Path node. The cost of the sort is, or should have been,
5439  * included in the cost of the Path node we're working from, but since it's
5440  * not split out, we have to re-figure it using cost_sort(). This is just
5441  * to label the Sort node nicely for EXPLAIN.
5442  *
5443  * limit_tuples is as for cost_sort (in particular, pass -1 if no limit)
5444  */
5445 static void
5447 {
5448  Plan *lefttree = plan->plan.lefttree;
5449  Path sort_path; /* dummy for result of cost_sort */
5450 
5451  /*
5452  * This function shouldn't have to deal with IncrementalSort plans because
5453  * they are only created from corresponding Path nodes.
5454  */
5455  Assert(IsA(plan, Sort));
5456 
5457  cost_sort(&sort_path, root, NIL,
5458  lefttree->total_cost,
5459  lefttree->plan_rows,
5460  lefttree->plan_width,
5461  0.0,
5462  work_mem,
5463  limit_tuples);
5464  plan->plan.startup_cost = sort_path.startup_cost;
5465  plan->plan.total_cost = sort_path.total_cost;
5466  plan->plan.plan_rows = lefttree->plan_rows;
5467  plan->plan.plan_width = lefttree->plan_width;
5468  plan->plan.parallel_aware = false;
5469  plan->plan.parallel_safe = lefttree->parallel_safe;
5470 }
5471 
5472 /*
5473  * bitmap_subplan_mark_shared
5474  * Set isshared flag in bitmap subplan so that it will be created in
5475  * shared memory.
5476  */
5477 static void
5479 {
5480  if (IsA(plan, BitmapAnd))
5481  bitmap_subplan_mark_shared(linitial(((BitmapAnd *) plan)->bitmapplans));
5482  else if (IsA(plan,